CVE-2026-5504

MEDIUM

PKCS7 CBC Padding Oracle — Plaintext Recovery

Title source: cna
STIX 2.1

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)

Core 1

Scores

CVSS v3 5.3
EPSS 0.0011
EPSS Percentile 1.6%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-354
Status published
Products (2)
wolfSSL/wolfSSL < 5.9.0
wolfssl/wolfssl < 5.9.0
Published Apr 09, 2026
Tracked Since Apr 10, 2026