CVE-2026-5504

MEDIUM

PKCS7 CBC Padding Oracle — Plaintext Recovery

Title source: cna

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.

References (1)

https://github.com/wolfSSL/wolfssl/pull/10088

Scores

CVSS v4 6.3

EPSS 0.0003

EPSS Percentile 7.0%

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

Details

CWE

CWE-354

Status published

Products (1)

wolfSSL/wolfSSL < 5.9.0

Published Apr 09, 2026

Tracked Since Apr 10, 2026