CVE-2026-5504

EUVD-2026-21235
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
wolfSSLCNA
6.3 MEDIUM
NETWORK
HIGH
NONE
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
wolfsslwolfssl
𝑥
≤ 5.9.0
CNA
Debian logo
Debian Releases
Debian Product
Codename
wolfssl
bookworm
vulnerable
bullseye
vulnerable
forky
vulnerable
sid
vulnerable
trixie
vulnerable
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
wolfssl
bionic
needs-triage
focal
needs-triage
jammy
needs-triage
noble
needs-triage
questing
needs-triage
xenial
needs-triage
Common Weakness Enumeration
References
https://github.com/wolfSSL/wolfssl/pull/10088