OpenSSL 4.0.1

OpenSSL 4.0.1 is a security patch release. The most severe CVE fixed in this release is High.

This release incorporates the following bug fixes and mitigations:

Fixed heap use-after-free in PKCS7_verify().
(CVE-2026-45447)

Fixed CMS AuthEnvelopedData processing may accept forged messages.
(CVE-2026-34182)

Fixed unbounded memory growth in the QUIC PATH_CHALLENGE handler.
(CVE-2026-34183)

Fixed double-free when checking OCSP stapled response.
(CVE-2026-35188)

Fixed NULL pointer dereference in QUIC server initial packet handling.
(CVE-2026-42764)

Fixed AES-OCB IV ignored on EVP_Cipher() path.
(CVE-2026-45445)

Fixed possible heap buffer overflow in ASN.1 multibyte string conversion.
(CVE-2026-7383)

Fixed out-of-bounds read in CMS password-based decryption.
(CVE-2026-9076)

Fixed heap buffer over-read in ASN.1 content parsing.
(CVE-2026-34180)

Fixed PKCS#12 files with PBMAC1 are accepted with short HMAC keys.
(CVE-2026-34181)

Fixed NULL dereference in certificate verification with OCSP Checking.
(CVE-2026-42765)

Fixed possible NULL dereference in password-dased CMS decryption.
(CVE-2026-42766)

Fixed NULL pointer dereference in CRMF EncryptedValue decryption.
(CVE-2026-42767)

Fixed multi-RecipientInfo Bleichenbacher Oracle in CMS_decrypt()
and PKCS7_decrypt().
(CVE-2026-42768)

Fixed trust anchor substitution via cert/issuer typo in CMP
rootCaKeyUpdate.
(CVE-2026-42769)

Fixed FFC-DH peer validation uses attacker-supplied q.
(CVE-2026-42770)

Fixed possible out of bounds read in X509_VERIFY_PARAM_set1_email().
(CVE-2026-42771)

Fixed incorrect tag processing for empty messages in AES-GCM-SIV
and AES-SIV modes.
(CVE-2026-45446)

Fixed a regression introduced in 4.0.0 that led to a openssl pkey
command crash when it was invoked to encrypt a private key with password
being provided interactively.

Fixed a regression introduced in 4.0.0 that led to openssl s_client -adv
command prematurely terminating a session when reading input of 16384 bytes
in one read() call.