CVE-2026-82455

Name	CVE-2026-82455
Description	RubyGems fails to re-validate path containment after filesystem symlink resolution during gem extraction. When a pre-existing symlink inside the destination directory points outside the extraction root, extracted files that appear to be written under the destination directory can instead be written outside of it, breaking the extraction safety boundary. The fix resolves the real path of the parent directory before writing and raises Gem::Package::PathError if it escapes the destination directory.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
rubygems (PTS)	bookworm	3.3.15-2+deb12u1	vulnerable
	trixie	3.6.7-2	vulnerable
	forky	4.0.18-1	fixed
	sid	4.0.20-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
rubygems	source	(unstable)	4.0.15-2

Notes

[trixie] - rubygems <no-dsa> (Minor issue)
[bookworm] - rubygems <postponed> (Minor issue)
https://github.com/ruby/rubygems/pull/9493
Fixed by (merge): https://github.com/ruby/rubygems/commit/103ca4230deacb31b9fcd813de109e83b5fc71ac