CVE-2026-4159

Name	CVE-2026-4159
Description	1-byte OOB heap read in wc_PKCS7_DecodeEnvelopedData via zero-length encrypted content. A vulnerability existed in wolfSSL 5.8.4 and earlier, where a 1-byte out-of-bounds heap read in wc_PKCS7_DecodeEnvelopedData could be triggered by a crafted CMS EnvelopedData message with zero-length encrypted content. Note that PKCS7 support is disabled by default.
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
wolfssl (PTS)	bullseye	4.6.0+p1-0+deb11u2	vulnerable
	bookworm	5.5.4-2+deb12u2	vulnerable
	trixie	5.7.2-0.1+deb13u1	vulnerable
	forky	5.8.4-1	vulnerable
	sid	5.9.0-0.1	vulnerable

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
wolfssl	source	(unstable)	(unfixed)

Notes

https://github.com/wolfSSL/wolfssl/pull/9945
Fixed by: https://github.com/wolfSSL/wolfssl/commit/d37b51c3cef6897e117364ab8b1a257e52a634c0 (v5.9.0-stable)