CVE-2026-6291

Name of the Vulnerable Software and Affected Versions wolfSSL (affected versions not specified)

Description A Bleichenbacher padding oracle exists in PKCS#7 KTRI decryption. When decrypting PKCS#7 EnvelopedData using RSA PKCS#1 v1.5 key transport, the software returns distinguishable error codes based on whether RSA padding validation failed or the decrypted content was malformed. An attacker can submit crafted EnvelopedData messages and observe these error responses to incrementally recover the encrypted Content Encryption Key (CEK), which is the symmetric key used to encrypt the actual data.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.