CVE-2026-87732

Name	CVE-2026-87732
Description	An issue was discovered in the mirage-crypto package before 2.2.0 for OCaml. The AES.GCM.authenticate_decrypt_into and Chacha20.authenticate_decrypt_into functions write the decrypted plaintext into a caller-provided buffer and only then compares the tag. On a forged tag, the functions returns false, but the destination buffer already holds the full plaintext.
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
ocaml-mirage-crypto (PTS)	bookworm	0.10.7-1	vulnerable
	trixie	2.0.0-1	vulnerable
	forky, sid	2.4.1-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
ocaml-mirage-crypto	source	(unstable)	2.2.0-1

Notes

[trixie] - ocaml-mirage-crypto <no-dsa> (Minor issue)
[bookworm] - ocaml-mirage-crypto <postponed> (Minor issue)
https://osv.dev/vulnerability/OSEC-2026-12
Fixed by: https://github.com/mirage/mirage-crypto/commit/25e7570aec91e092b347561c23f84b6ec39e7163 (v2.2.0)