Astro: Cache Poisoning due to incorrect error handling when if-match header is malformed

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS

• CVE-2026-41322: 0.29% estimated exploitation activity in the next 30 days; percentile 21.16 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary Requesting a static JS/CSS resource from the astro path with an incorrect or malformed if-match header returns a 500 error with a one-year cache lifetime instead of 412 in some cases. As a result, all subsequent requests to that file — regardless of the if-match header — will be served a 5xx error instead of the file until the cache expires. Sending an incorrect or malformed if-match header should always return a 412 error without any cache headers, which is not the current behavior. Affected Versions - astro@5.14.1 - @astrojs/node@9.4.4 Proof of Concept Run the following command: If a 5xx error is not returned, inspect the resources via the browser's web inspector and select another CSS/JS file to request until a 5xx error is returned. The behavior generally defaults to a 5xx response. Note that all static files are immutable, so the cache must be purged or disabled to reproduce reliably. A response similar to the following is expected from CloudFront: The above is not the…

Published by the source

23 Apr 2026, 14:36 UTC

Last modified by the source

5 May 2026, 16:05 UTC

Source last checked

26 Oct 2026, 12:51 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-c57f-mm3j-27q9

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-c57f-mm3j-27q9

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# Patch Next advisory brief: CVE-2026-41322

Advisory: Astro: Cache Poisoning due to incorrect error handling when if-match header is malformed
IDs: CVE-2026-41322, GHSA-c57f-mm3j-27q9
Record: https://patchnext.com/advisories/cve-2026-41322 (revision 2, source checked 26 Oct 2026, 12:51 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @astrojs/node 10.0.5. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @astrojs/node: affected < 10.0.5; fixed in 10.0.5

## Suggested inspection (read-only)
- `npm ls @astrojs/node --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on @astrojs/node.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-c57f-mm3j-27q9 (OSV record GHSA-c57f-mm3j-27q9 lists affected ranges: npm @astrojs/node >=0 <10.0.5 (fixed))
- Verified: https://github.com/advisories/GHSA-c57f-mm3j-27q9 (GitHub-reviewed advisory GHSA-c57f-mm3j-27q9 lists affected ranges: npm @astrojs/node >=0 <10.0.5)

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