YARD static cache reads raw traversal paths before router sanitization

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:L/I:N/A:N

EPSS

• CVE-2026-49342: 0.33% estimated exploitation activity in the next 30 days; percentile 26.42 (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 YARD's static cache lookup reads a request path before the router's path cleanup runs. When a server is configured with a document root, a traversal path such as /../yard-cache-secret.html is joined against that root and can return a readable sibling .html file outside the intended static tree. The potential security risk seems low, as only html-ending files can be read, but still the risk of reading arbitrary html files is a confiendtiality issue in itself, which is why we decided to report. Please let us know if this is out of your project's scope. Details The --docroot CLI option stores the configured directory in serveroptions[:DocumentRoot] at lib/yard/cli/server.rb:198, and adapter initialization copies that value into adapter.documentroot at lib/yard/server/adapter.rb:76. For Rack requests, RackAdapter#call builds a request object from the Rack environment at lib/yard/server/rackadapter.rb:58 and passes it to router.call(request) at lib/yard/server/rackadapter.rb:60.…

Published by the source

26 Jun 2026, 22:29 UTC

Last modified by the source

26 Jun 2026, 22:29 UTC

Source last checked

26 Oct 2026, 15:52 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-pxcc-8665-phx8

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# Patch Next advisory brief: CVE-2026-49342

Advisory: YARD static cache reads raw traversal paths before router sanitization
IDs: CVE-2026-49342, GHSA-pxcc-8665-phx8
Record: https://patchnext.com/advisories/cve-2026-49342 (revision 1, source checked 26 Oct 2026, 15:52 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: yard 0.9.44. A vendor fix does not mean a deployment is fixed.

## Affected components
- RubyGems yard: affected < 0.9.44; fixed in 0.9.44

## Suggested inspection (read-only)
- RubyGems yard: check the installed version with your package manager.

## 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 yard.
- 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://github.com/advisories/GHSA-pxcc-8665-phx8 (GitHub-reviewed advisory GHSA-pxcc-8665-phx8 lists affected ranges: RubyGems yard >=0 <0.9.44)

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