[GHSA-qwww-vcr4-c8h2] React Router: RSC Mode CSRF Bypass Allows Action Execution Before 400 Response

[brookslybrand]

Updates

• Affected products

Comments
We backported the fix to React Router v7, so the ranges need to be updated:

• React Router advisory
• PR

[github]

Hi there @brophdawg11! A community member has suggested an improvement to your security advisory. If approved, this change will affect the global advisory listed at github.com/advisories. It will not affect the version listed in your project repository.

This change will be reviewed by our Security Curation Team. If you have thoughts or feedback, please share them in a comment here! If this PR has already been closed, you can start a new community contribution for this advisory

[Copilot]

Pull request overview

Updates React Router advisory ranges for patched v7 and v8 releases.

Changes:

• Adds separate affected ranges for v7 and v8.
• Records fixed versions and last-known affected ranges.

Comments suppressed due to low confidence (1)

advisories/github-reviewed/2026/07/GHSA-qwww-vcr4-c8h2/GHSA-qwww-vcr4-c8h2.json:51

• As with the v7 range, an OSV fixed event must contain the exact boundary version rather than a comparator expression. ">= 8.3.0" is not a valid package version and may prevent consumers from closing this affected interval correctly.

              "fixed": ">= 8.3.0"

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[raulariton]

Hi, until this version update goes through, we are blocked for a project release as it causes the audit step in our pipeline to fail. Would be great to have this merged ASAP.

Thank you.

[j-hannes]

Independent confirmation that the proposed < 7.18.2 boundary is correct, from diffing the published tarballs rather than reading the changelog.

Comparing react-router@7.18.1 and 7.18.2 dist output — normalising the chunk-hash renames, which account for most of the raw diff — leaves one substantive logic change. The RSC action path now catches the CSRF error and rewrites the request to GET before continuing, so the action no longer executes ahead of the 400:

} catch (error) {
  onError?.(error);
  potentialCSRFAttackError = error;
  request = new Request(request.url, {
    method: "GET",
    headers: request.headers,
    signal: request.signal
  });
}
if (!potentialCSRFAttackError) {

That matches remix-run/react-router#15311 ("harden RSC CSRF codepaths") as backported by remix-run/react-router#15353 ("Backport RSC CSRF hardening to v7"), and the 7.18.2 changelog entry ("Harden RSC CSRF codepaths"). So 7.18.2 is patched, and the current single < 8.3.0 range reports it as a false positive.

The two-range split in this PR also looks preferable to the "fixed": "7.18.2, 8.3.0" shape used in some sibling PRs, since it keeps the v7 and v8 lines independently expressible.