CVE-2026-49342 YARD static cache reads raw traversal paths before router sanitization
Attackers can read arbitrary HTML files outside the intended directory if YARD is configured with a document root, due to premature path resolution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-49342?
CVE-2026-49342 is a medium-severity path traversal vulnerability in lsegal yard, published on 19 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
YARD is a documentation generation tool for the Ruby programming language. Prior to version 0.9.44, 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. Version 0.9.44 patches the issue.
Weakness: CWE-22
Which versions are affected by CVE-2026-49342?
2 open source packages ship an affected version, including yard.
| Package | Affected | Fixed in |
|---|---|---|
yard RubyGems | All versions | 0.9.44 |
yard RubyGems | All versions | 0.9.44 |
How do I fix CVE-2026-49342?
Upgrade yard to 0.9.44 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-49342 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-49342 exists.
Sources
Also known as DEBIAN-CVE-2026-49342, GHSA-pxcc-8665-phx8, OESA-2026-2851, OESA-2026-2852, UBUNTU-CVE-2026-49342.