CVE-2026-42767

Name	CVE-2026-42767
Description	Issue summary: An attacker-controlled CMP (Certificate Management Protocol) server could trigger a NULL pointer dereference in a CMP client application. Impact summary: A NULL pointer dereference causes a crash of the application and a Denial of Service. An attacker controlling a CMP server (or acting as a man-in-the-middle) could craft a CMP response containing a CRMF (Certificate Request Message Format) CertRepMessage with an EncryptedValue structure where the symmAlg field has an algorithm OID but no parameters field. When the OpenSSL CMP client processes this response, the NULL dereference occurs, causing a crash of the CMP client. Applications that process untrusted CMP/CRMF messages may be affected. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.
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	1139674

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
openssl (PTS)	bullseye	1.1.1w-0+deb11u1	fixed
	bullseye (security)	1.1.1w-0+deb11u8	fixed
	bookworm	3.0.20-1~deb12u1	vulnerable
	bookworm (security)	3.0.20-1~deb12u2	vulnerable
	trixie	3.5.6-1~deb13u1	vulnerable
	trixie (security)	3.5.6-1~deb13u2	fixed
	forky, sid	3.6.3-1	fixed

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

Package	Type	Release	Fixed Version	Debian Bugs
openssl	source	bullseye	(not affected)
openssl	source	trixie	3.5.6-1~deb13u2
openssl	source	(unstable)	3.6.3-1	1139674

Notes

[bookworm] - openssl <no-dsa> (Minor issue; can be fixed in next update)
[bullseye] - openssl <not-affected> (Vulnerable code introduced later)
https://openssl-library.org/news/secadv/20260609.txt
Fixed by: https://github.com/openssl/openssl/commit/61a86a8cd73546c9fea916f3d304c1293e05c046 (openssl-3.0.21)
Introduced with: https://github.com/openssl/openssl/commit/a61b7f2fa6de3bf8d5b1436e66c52d6bf7150ae4