CVE-2026-5504

Name	CVE-2026-5504
Description	A padding oracle exists in wolfSSL's PKCS7 CBC decryption that could allow an attacker to recover plaintext through repeated decryption queries with modified ciphertext. In previous versions of wolfSSL the interior padding bytes are not validated.
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, sid	5.9.0-0.2	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/10088
Fixed by (merge): https://github.com/wolfSSL/wolfssl/commit/750f3b119e04a8c83bd601014fbd47cdc8856d3c (v5.9.1-stable)