CVE-2026-5504
Padding Oracle Vulnerability in wolfSSL PKCS7 CBC Decryption
Publication date: 2026-04-09
Last updated on: 2026-04-29
Assigner: wolfSSL Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| wolfssl | wolfssl | to 5.9.0 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-354 | The product does not validate or incorrectly validates the integrity check values or "checksums" of a message. This may prevent it from detecting if the data has been modified or corrupted in transmission. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability is a padding oracle issue in wolfSSL's PKCS7 CBC decryption. It allows an attacker to recover plaintext data by making repeated decryption attempts with modified ciphertext. The problem arises because, in previous versions of wolfSSL, the interior padding bytes were not properly validated during decryption.
How can this vulnerability impact me? :
An attacker exploiting this vulnerability could recover sensitive plaintext data from encrypted communications or stored data by repeatedly querying the decryption function with altered ciphertext. This could lead to unauthorized disclosure of confidential information.