CVE-2026-10512

Name	CVE-2026-10512
Description	The X25519 x86_64 assembly implementation fails to clear the most significant bit during the final modular reduction, so the computed result may not be fully reduced modulo the field prime 2^255 - 19. This can leave the field element in a non-canonical form, producing an incorrect result from the scalar multiplication and potentially a wrong shared secret. The final carry-propagation chains in the x64 and AVX2 reduction routines could overflow into the top bit, and the high limb was not masked afterward, so the 255-bit field element was left non-canonical.
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
	bookworm (security)	5.5.4-2+deb12u3	vulnerable
	trixie	5.7.2-0.1+deb13u1	vulnerable
	sid	5.9.2-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
wolfssl	source	bookworm	(unfixed)	end-of-life
wolfssl	source	(unstable)	5.9.2-1

Notes

[trixie] - wolfssl <no-dsa> (Minor issue; can be fixed in point release)
[bookworm] - wolfssl <end-of-life> (EOL in bookworm LTS)
[bullseye] - wolfssl <postponed> (Minor issue)
https://github.com/wolfSSL/wolfssl/pull/10536 (v5.9.2-stable)