CVE-2026-5504
PKCS7 CBC Padding Oracle — Plaintext Recovery
MEDIUM
5.3
CVSS Score
Published: April 9, 2026 at 10:33 PM UTC
Updated: June 17, 2026 at 10:59 AM UTC
1 product affected across 1 vendorwolfSSL
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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.1%
SSVC
No known exploit
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.
Remediation
No guide yetNo remediation guidance has been written for this CVE yet. What the record does show:
Patch and advisory references
References (1)
SSVC — Action Prioritization
SSVCNo known exploitNot automatablePartial impact
SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.
CVSS
- Attack Vector
- NETWORK
- Complexity
- LOW
- Privileges
- NONE
- User Interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality
- LOW
- Integrity
- NONE
- Availability
- NONE
Vector?
Quick Info
StatusANALYZED
CWE
CWE-354
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