cryptography: PKCS#7 EnvelopedData decryption exposes a Bleichenbacher oracle through distinguishable errors and timing

Summary pkcs7decryptder, pkcs7decryptpem, and pkcs7decryptsmime reported the outcome of decrypting a RecipientInfo's encryptedKey in several distinguishable ways, one of which disclosed the exact length recovered from the RSA operation. The same distinction was also observable by timing. An...

CVE-2026-69247 cryptography: PKCS#7 EnvelopedData decryption exposes a Bleichenbacher oracle through distinguishable errors and timing

cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. From 44.0.0 until 50.0.0, pkcs7decryptder, pkcs7decryptpem, and pkcs7decryptsmime reported the outcome of decrypting a RecipientInfo's encryptedKey in several distinguishable ways, one of which...

CVE-2026-6291

Bleichenbacher padding oracle in PKCS7 KTRI decryption. When decrypting PKCS7 EnvelopedData using RSA PKCS1 v1.5 key transport, wolfSSL returned distinguishable error codes depending on whether RSA padding validation failed versus whether the decrypted content was malformed. An attacker able to...

CVE-2026-6291

Bleichenbacher padding oracle in PKCS7 KTRI decryption. When decrypting PKCS7 EnvelopedData using RSA PKCS1 v1.5 key transport, wolfSSL returned distinguishable error codes depending on whether RSA padding validation failed versus whether the decrypted content was malformed. An attacker able to...

CVE-2026-6291 Bleichenbacher padding oracle in PKCS#7 KTRI RSA PKCS#1 v1.5 decryption

Bleichenbacher padding oracle in PKCS7 KTRI decryption. When decrypting PKCS7 EnvelopedData using RSA PKCS1 v1.5 key transport, wolfSSL returned distinguishable error codes depending on whether RSA padding validation failed versus whether the decrypted content was malformed. An attacker able to...

CVE-2026-6291 Bleichenbacher padding oracle in PKCS#7 KTRI RSA PKCS#1 v1.5 decryption

Bleichenbacher padding oracle in PKCS7 KTRI decryption. When decrypting PKCS7 EnvelopedData using RSA PKCS1 v1.5 key transport, wolfSSL returned distinguishable error codes depending on whether RSA padding validation failed versus whether the decrypted content was malformed. An attacker able to...

EUVD-2026-39482

Bleichenbacher padding oracle in PKCS7 KTRI decryption. When decrypting PKCS7 EnvelopedData using RSA PKCS1 v1.5 key transport, wolfSSL returned distinguishable error codes depending on whether RSA padding validation failed versus whether the decrypted content was malformed. An attacker able to...

CVE-2026-6291

CVE-2026-6291 affects wolfSSL (v4.0) and describes a Bleichenbacher padding oracle in PKCS#7 KTRI RSA PKCS#1 v1.5 decryption used for EnvelopedData. The vulnerability arises because error codes differed between RSA padding validation failure and malformed decrypted content, enabling an attacker t...

PT-2026-52530

Bleichenbacher padding oracle in PKCS7 KTRI decryption. When decrypting PKCS7 EnvelopedData using RSA PKCS1 v1.5 key transport, wolfSSL returned distinguishable error codes depending on whether RSA padding validation failed versus whether the decrypted content was malformed. An attacker able to...

Timing Attack

Overview authlib is a library in building OAuth and OpenID Connect servers. Affected versions of this package are vulnerable to Timing Attack via the unwrap length check in jwealgs.py. An attacker can recover the CEK and decrypt or forge JWE tokens by sending malformed RSA15 ciphertexts and...