Vulnerabilities (CVE)

Astro is a web framework. In versions 9.0.0 through 9.5.3, Astro server actions have no default request body size limit, which can lead to memory exhaustion DoS. A single large POST to a valid action endpoint can crash the server process on memory-constrained deployments. On-demand rendered sites built with Astro can define server actions, which automatically parse incoming request bodies (JSON or FormData). The body is buffered entirely into memory with no size limit — a single oversized reques ... Astro is a web framework. In versions 9.0.0 through 9.5.3, Astro server actions have no default request body size limit, which can lead to memory exhaustion DoS. A single large POST to a valid action endpoint can crash the server process on memory-constrained deployments. On-demand rendered sites built with Astro can define server actions, which automatically parse incoming request bodies (JSON or FormData). The body is buffered entirely into memory with no size limit — a single oversized request is sufficient to exhaust the process heap and crash the server. Astro's Node adapter (`mode: 'standalone'`) creates an HTTP server with no body size protection. In containerized environments, the crashed process is automatically restarted, and repeated requests cause a persistent crash-restart loop. Action names are discoverable from HTML form attributes on any public page, so no authentication is required. The vulnerability allows unauthenticated denial of service against SSR standalone deployments using server actions. A single oversized request crashes the server process, and repeated requests cause a persistent crash-restart loop in containerized environments. Version 9.5.4 contains a fix.

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Astro is a web framework. Prior to version 9.5.4, Server-Side Rendered pages that return an error with a prerendered custom error page (eg. `404.astro` or `500.astro`) are vulnerable to SSRF. If the `Host:` header is changed to an attacker's server, it will be fetched on `/500.html` and they can redirect this to any internal URL to read the response body through the first request. An attacker who can access the application without `Host:` header validation (eg. through finding the origin IP behi ... Astro is a web framework. Prior to version 9.5.4, Server-Side Rendered pages that return an error with a prerendered custom error page (eg. `404.astro` or `500.astro`) are vulnerable to SSRF. If the `Host:` header is changed to an attacker's server, it will be fetched on `/500.html` and they can redirect this to any internal URL to read the response body through the first request. An attacker who can access the application without `Host:` header validation (eg. through finding the origin IP behind a proxy, or just by default) can fetch their own server to redirect to any internal IP. With this they can fetch cloud metadata IPs and interact with services in the internal network or localhost. For this to be vulnerable, a common feature needs to be used, with direct access to the server (no proxies). Version 9.5.4 fixes the issue.

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Astro is a web framework for content-driven websites. Versions 11.0.3 through 12.6.5 are vulnerable to SSRF when using Astro's Cloudflare adapter. When configured with output: 'server' while using the default imageService: 'compile', the generated image optimization endpoint doesn't check the URLs it receives, allowing content from unauthorized third-party domains to be served. a A bug in impacted versions of the @astrojs/cloudflare adapter for deployment on Cloudflare’s infrastructure, allows a ... Astro is a web framework for content-driven websites. Versions 11.0.3 through 12.6.5 are vulnerable to SSRF when using Astro's Cloudflare adapter. When configured with output: 'server' while using the default imageService: 'compile', the generated image optimization endpoint doesn't check the URLs it receives, allowing content from unauthorized third-party domains to be served. a A bug in impacted versions of the @astrojs/cloudflare adapter for deployment on Cloudflare’s infrastructure, allows an attacker to bypass the third-party domain restrictions and serve any content from the vulnerable origin. This issue is fixed in version 12.6.6.

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Astro is a web framework. Versions 5.15.7 and below have a double URL encoding bypass which allows any unauthenticated attacker to bypass path-based authentication checks in Astro middleware, granting unauthorized access to protected routes. While the original CVE-2025-64765 was fixed in v5.15.8, the fix is insufficient as it only decodes once. By using double-encoded URLs, attackers can still bypass authentication and access any route protected by middleware pathname checks. This issue is fixed ... Astro is a web framework. Versions 5.15.7 and below have a double URL encoding bypass which allows any unauthenticated attacker to bypass path-based authentication checks in Astro middleware, granting unauthorized access to protected routes. While the original CVE-2025-64765 was fixed in v5.15.8, the fix is insufficient as it only decodes once. By using double-encoded URLs, attackers can still bypass authentication and access any route protected by middleware pathname checks. This issue is fixed in version 5.15.8.

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Astro is a web framework. Prior to version 5.14.2, Astro reflects the value in `X-Forwarded-Host` in output when using `Astro.url` without any validation. It is common for web servers such as nginx to route requests via the `Host` header, and forward on other request headers. As such as malicious request can be sent with both a `Host` header and an `X-Forwarded-Host` header where the values do not match and the `X-Forwarded-Host` header is malicious. Astro will then return the malicious value. T ... Astro is a web framework. Prior to version 5.14.2, Astro reflects the value in `X-Forwarded-Host` in output when using `Astro.url` without any validation. It is common for web servers such as nginx to route requests via the `Host` header, and forward on other request headers. As such as malicious request can be sent with both a `Host` header and an `X-Forwarded-Host` header where the values do not match and the `X-Forwarded-Host` header is malicious. Astro will then return the malicious value. This could result in any usages of the `Astro.url` value in code being manipulated by a request. For example if a user follows guidance and uses `Astro.url` for a canonical link the canonical link can be manipulated to another site. It is theoretically possible that the value could also be used as a login/registration or other form URL as well, resulting in potential redirecting of login credentials to a malicious party. As this is a per-request attack vector the surface area would only be to the malicious user until one considers that having a caching proxy is a common setup, in which case any page which is cached could persist the malicious value for subsequent users. Many other frameworks have an allowlist of domains to validate against, or do not have a case where the headers are reflected to avoid such issues. This could affect anyone using Astro in an on-demand/dynamic rendering mode behind a caching proxy. Version 5.14.2 contains a fix for the issue.

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Astro is a web framework that includes an image proxy. In versions 5.13.4 and later before 5.13.10, the image proxy domain validation can be bypassed by using backslashes in the href parameter, allowing server-side requests to arbitrary URLs. This can lead to server-side request forgery (SSRF) and potentially cross-site scripting (XSS). This vulnerability exists due to an incomplete fix for CVE-2025-58179. Fixed in 5.13.10.

Astro is a web framework for content-driven websites. In versions 5.2.0 through 5.12.7, there is an Open Redirect vulnerability in the trailing slash redirection logic when handling paths with double slashes. This allows an attacker to redirect users to arbitrary external domains by crafting URLs such as https://mydomain.com//malicious-site.com/. This increases the risk of phishing and other social engineering attacks. This affects sites that use on-demand rendering (SSR) with the Node or Cloudf ... Astro is a web framework for content-driven websites. In versions 5.2.0 through 5.12.7, there is an Open Redirect vulnerability in the trailing slash redirection logic when handling paths with double slashes. This allows an attacker to redirect users to arbitrary external domains by crafting URLs such as https://mydomain.com//malicious-site.com/. This increases the risk of phishing and other social engineering attacks. This affects sites that use on-demand rendering (SSR) with the Node or Cloudflare adapters. It does not affect static sites, or sites deployed to Netlify or Vercel. This issue is fixed in version 5.12.8. To work around this issue at the network level, block outgoing redirect responses with a Location header value that starts with `//`.

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Astro is a web framework. In Astro versions 2.16.0 up to but excluding 5.15.5 which utilizeon-demand rendering, request headers `x-forwarded-proto` and `x-forwarded-port` are insecurely used, without sanitization, to build the URL. This has several consequences, the most important of which are: middleware-based protected route bypass (only via `x-forwarded-proto`), DoS via cache poisoning (if a CDN is present), SSRF (only via `x-forwarded-proto`), URL pollution (potential SXSS, if a CDN is prese ... Astro is a web framework. In Astro versions 2.16.0 up to but excluding 5.15.5 which utilizeon-demand rendering, request headers `x-forwarded-proto` and `x-forwarded-port` are insecurely used, without sanitization, to build the URL. This has several consequences, the most important of which are: middleware-based protected route bypass (only via `x-forwarded-proto`), DoS via cache poisoning (if a CDN is present), SSRF (only via `x-forwarded-proto`), URL pollution (potential SXSS, if a CDN is present), and WAF bypass. Version 5.15.5 contains a patch.

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Astro is a web framework. Starting in version 5.2.0 and prior to version 5.15.6, a Reflected Cross-Site Scripting (XSS) vulnerability exists in Astro's development server error pages when the `trailingSlash` configuration option is used. An attacker can inject arbitrary JavaScript code that executes in the victim's browser context by crafting a malicious URL. While this vulnerability only affects the development server and not production builds, it could be exploited to compromise developer envi ... Astro is a web framework. Starting in version 5.2.0 and prior to version 5.15.6, a Reflected Cross-Site Scripting (XSS) vulnerability exists in Astro's development server error pages when the `trailingSlash` configuration option is used. An attacker can inject arbitrary JavaScript code that executes in the victim's browser context by crafting a malicious URL. While this vulnerability only affects the development server and not production builds, it could be exploited to compromise developer environments through social engineering or malicious links. Version 5.15.6 fixes the issue.

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Astro is a web framework. Prior to version 5.15.8, a mismatch exists between how Astro normalizes request paths for routing/rendering and how the application’s middleware reads the path for validation checks. Astro internally applies decodeURI() to determine which route to render, while the middleware uses context.url.pathname without applying the same normalization (decodeURI). This discrepancy may allow attackers to reach protected routes using encoded path variants that pass routing but bypas ... Astro is a web framework. Prior to version 5.15.8, a mismatch exists between how Astro normalizes request paths for routing/rendering and how the application’s middleware reads the path for validation checks. Astro internally applies decodeURI() to determine which route to render, while the middleware uses context.url.pathname without applying the same normalization (decodeURI). This discrepancy may allow attackers to reach protected routes using encoded path variants that pass routing but bypass validation checks. This issue has been patched in version 5.15.8.

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Astro is a web framework. Prior to version 5.15.9, when using Astro's Cloudflare adapter (@astrojs/cloudflare) with output: 'server', the image optimization endpoint (/_image) contains a critical vulnerability in the isRemoteAllowed() function that unconditionally allows data: protocol URLs. This enables Cross-Site Scripting (XSS) attacks through malicious SVG payloads, bypassing domain restrictions and Content Security Policy protections. This issue has been patched in version 5.15.9.

Astro is a web framework for content-driven websites. In versions of astro before 5.13.2 and 4.16.18, the image optimization endpoint in projects deployed with on-demand rendering allows images from unauthorized third-party domains to be served. On-demand rendered sites built with Astro include an /_image endpoint which returns optimized versions of images. A bug in impacted versions of astro allows an attacker to bypass the third-party domain restrictions by using a protocol-relative URL as the ... Astro is a web framework for content-driven websites. In versions of astro before 5.13.2 and 4.16.18, the image optimization endpoint in projects deployed with on-demand rendering allows images from unauthorized third-party domains to be served. On-demand rendered sites built with Astro include an /_image endpoint which returns optimized versions of images. A bug in impacted versions of astro allows an attacker to bypass the third-party domain restrictions by using a protocol-relative URL as the image source, e.g. /_image?href=//example.com/image.png. This vulnerability is fixed in 5.13.2 and 4.16.18.

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The Astro web framework has a DOM Clobbering gadget in the client-side router starting in version 3.0.0 and prior to version 4.16.1. It can lead to cross-site scripting (XSS) in websites enables Astro's client-side routing and has *stored* attacker-controlled scriptless HTML elements (i.e., `iframe` tags with unsanitized `name` attributes) on the destination pages. This vulnerability can result in cross-site scripting (XSS) attacks on websites that built with Astro that enable the client-side ro ... The Astro web framework has a DOM Clobbering gadget in the client-side router starting in version 3.0.0 and prior to version 4.16.1. It can lead to cross-site scripting (XSS) in websites enables Astro's client-side routing and has *stored* attacker-controlled scriptless HTML elements (i.e., `iframe` tags with unsanitized `name` attributes) on the destination pages. This vulnerability can result in cross-site scripting (XSS) attacks on websites that built with Astro that enable the client-side routing with `ViewTransitions` and store the user-inserted scriptless HTML tags without properly sanitizing the `name` attributes on the page. Version 4.16.1 contains a patch for this issue.

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Astro is a web framework for content-driven websites. In affected versions a bug in Astro’s CSRF-protection middleware allows requests to bypass CSRF checks. When the `security.checkOrigin` configuration option is set to `true`, Astro middleware will perform a CSRF check. However, a vulnerability exists that can bypass this security. A semicolon-delimited parameter is allowed after the type in `Content-Type`. Web browsers will treat a `Content-Type` such as `application/x-www-form-urlencoded; ab ... Astro is a web framework for content-driven websites. In affected versions a bug in Astro’s CSRF-protection middleware allows requests to bypass CSRF checks. When the `security.checkOrigin` configuration option is set to `true`, Astro middleware will perform a CSRF check. However, a vulnerability exists that can bypass this security. A semicolon-delimited parameter is allowed after the type in `Content-Type`. Web browsers will treat a `Content-Type` such as `application/x-www-form-urlencoded; abc` as a `simple request` and will not perform preflight validation. In this case, CSRF is not blocked as expected. Additionally, the `Content-Type` header is not required for a request. This issue has been addressed in version 4.16.17 and all users are advised to upgrade. There are no known workarounds for this vulnerability.

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Astro is a web framework for content-driven websites. A bug in the build process allows any unauthenticated user to read parts of the server source code. During build, along with client assets such as css and font files, the sourcemap files **for the server code** are moved to a publicly-accessible folder. Any outside party can read them with an unauthorized HTTP GET request to the same server hosting the rest of the website. While some server files are hashed, making their access obscure, the f ... Astro is a web framework for content-driven websites. A bug in the build process allows any unauthenticated user to read parts of the server source code. During build, along with client assets such as css and font files, the sourcemap files **for the server code** are moved to a publicly-accessible folder. Any outside party can read them with an unauthorized HTTP GET request to the same server hosting the rest of the website. While some server files are hashed, making their access obscure, the files corresponding to the file system router (those in `src/pages`) are predictably named. For example. the sourcemap file for `src/pages/index.astro` gets named `dist/client/pages/index.astro.mjs.map`. This vulnerability is the root cause of issue #12703, which links to a simple stackblitz project demonstrating the vulnerability. Upon build, notice the contents of the `dist/client` (referred to as `config.build.client` in astro code) folder. All astro servers make the folder in question accessible to the public internet without any authentication. It contains `.map` files corresponding to the code that runs on the server. All **server-output** projects on Astro 5 versions **v5.0.3** through **v5.0.7**, that have **sourcemaps enabled**, either directly or through an add-on such as `sentry`, are affected. The fix for **server-output** projects was released in **[email protected]**. Additionally, all **static-output** projects built using Astro 4 versions **4.16.17 or older**, or Astro 5 versions **5.0.8 or older**, that have **sourcemaps enabled** are also affected. The fix for **static-output** projects was released in **[email protected]**, and backported to Astro v4 in **[email protected]**. The immediate impact is limited to source code. Any secrets or environment variables are not exposed unless they are present verbatim in the source code. There is no immediate loss of integrity within the the vulnerable server. However, it is possible to subsequently discover another vulnerability via the revealed source code . There is no immediate impact to availability of the vulnerable server. However, the presence of an unsafe regular expression, for example, can quickly be exploited to subsequently compromise the availability. The fix for **server-output** projects was released in **[email protected]**, and the fix for **static-output** projects was released in **[email protected]** and backported to Astro v4 in **[email protected]**. Users are advised to update immediately if they are using sourcemaps or an integration that enables sourcemaps.

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Astro is a web framework. Prior to version 5.14.3, a vulnerability has been identified in the Astro framework's development server that allows arbitrary local file read access through the image optimization endpoint. The vulnerability affects Astro development environments and allows remote attackers to read any image file accessible to the Node.js process on the host system. This issue has been patched in version 5.14.3.

Astro is a web framework. Prior to version 5.15.8, a reflected XSS vulnerability is present when the server islands feature is used in the targeted application, regardless of what was intended by the component template(s). This issue has been patched in version 5.15.8.