CVE-2026-42327

Name	CVE-2026-42327
Description	rust-openssl provides OpenSSL bindings for the Rust programming language. From 0.9.7 to before 0.10.79, X509Ref::ocsp_responders returns OCSP responder URLs from a certificate's AIA extension as OpensslString, whose Deref<Target = str> wraps the raw bytes with str::from_utf8_unchecked. OpenSSL does not enforce that the underlying IA5String is ASCII, so a certificate with non-UTF-8 bytes in its OCSP accessLocation causes safe Rust code to construct a &str that violates the UTF-8 invariant — resulting in undefined behavior. This vulnerability is fixed in 0.10.79.
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)
Debian Bugs	1136787

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
rust-openssl (PTS)	bullseye	0.10.29-1	vulnerable
	bullseye (security)	0.10.29-1+deb11u1	vulnerable
	bookworm	0.10.45-1	vulnerable
	trixie	0.10.72-1	vulnerable
	forky	0.10.73-1	vulnerable
	sid	0.10.78-1	vulnerable

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
rust-openssl	source	(unstable)	(unfixed)			1136787

https://github.com/rust-openssl/rust-openssl/security/advisories/GHSA-xp3w-r5p5-63rr