Astro development server error page vulnerable to reflected Cross-site Scripting
Description
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.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
astronpm | >= 5.2.0, < 5.15.6 | 5.15.6 |
Affected products
1Patches
1790d9425f39bMerge commit from fork
1 file changed · +3 −2
packages/astro/src/template/4xx.ts+3 −2 modified@@ -134,10 +134,11 @@ export function trailingSlashMismatchTemplate( pathname: string, trailingSlash: 'always' | 'never' | 'ignore', ) { - const corrected = + const corrected = escape( trailingSlash === 'always' ? appendForwardSlash(pathname) - : removeTrailingForwardSlash(pathname); + : removeTrailingForwardSlash(pathname), + ); return template({ pathname, statusCode: 404,
Vulnerability mechanics
Generated by null/stub on May 9, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.
References
6- github.com/advisories/GHSA-w2vj-39qv-7vh7ghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2025-64745ghsaADVISORY
- github.com/withastro/astro/blob/5bc37fd5cade62f753aef66efdf40f982379029a/packages/astro/src/template/4xx.tsghsax_refsource_MISCWEB
- github.com/withastro/astro/commit/790d9425f39bbbb462f1c27615781cd965009f91ghsax_refsource_MISCWEB
- github.com/withastro/astro/pull/12994ghsax_refsource_MISCWEB
- github.com/withastro/astro/security/advisories/GHSA-w2vj-39qv-7vh7ghsax_refsource_CONFIRMWEB
News mentions
0No linked articles in our index yet.