OpenSSL Security Bulletin: 4 CVEs (UAF, CMS Forgery, DoS, Double-free) with Patch Versions

OpenSSL Security Advisory (June 9, 2026) 1. Heap Use-After-Free in the PKCS7_verify() Function (CVE-2026-45447) Vulnerability Overview: Crafted PKCS7 or S/MIME signed messages may trigger a use-after-free during PKCS7 signature verification. Affected Versions: - OpenSSL 4.0, 3.6, 3.5, 3.4, 3.0, 1.1.1, and 1.0.2 are affected. - The FIPS module is not affected. Remediation: - OpenSSL 4.0 users should upgrade to OpenSSL 4.0.1. - OpenSSL 3.6 users should upgrade to OpenSSL 3.6.3. - OpenSSL 3.5 users should upgrade to OpenSSL 3.5.7. - OpenSSL 3.4 users should upgrade to OpenSSL 3.4.6. - OpenSSL 3.0 users should upgrade to OpenSSL 3.0.21. - OpenSSL 1.1.1 users should upgrade to OpenSSL 1.1.1h. - OpenSSL 1.0.2 users should upgrade to OpenSSL 1.0.2q. 2. CMS AuthEnvelopedData Processing May Accept Forged Messages (CVE-2026-34182) Vulnerability Overview: Cryptographic Message Syntax (CMS) processing failed to perform sufficient input validation on the ciphertext and tag length fields of the AuthEnvelopedData container, potentially leading to various compromises. Affected Versions: - OpenSSL 4.0, 3.6, 3.5, 3.4, and 3.0 are affected. - The FIPS module is not affected. Remediation: - OpenSSL 4.0 users should upgrade to OpenSSL 4.0.1. - OpenSSL 3.6 users should upgrade to OpenSSL 3.6.3. - OpenSSL 3.5 users should upgrade to OpenSSL 3.5.7. - OpenSSL 3.4 users should upgrade to OpenSSL 3.4.6. - OpenSSL 3.0 users should upgrade to OpenSSL 3.0.21. - OpenSSL 1.1.1 and 1.0.2 are not affected. 3. Unbounded Memory Growth in the QUIC PATH CHALLENGE Handler (CVE-2026-34183) Vulnerability Overview: A remote peer can exhaust heap memory on a QUIC server or client by sending packets containing QUIC PATH CHALLENGE frames. Affected Versions: - OpenSSL 3.4, 3.5, 3.6, and 4.0 are affected. - The FIPS module is not affected. Remediation: - OpenSSL 3.4 users should upgrade to OpenSSL 3.4.6. - OpenSSL 3.5 users should upgrade to OpenSSL 3.5.7. - OpenSSL 3.6 users should upgrade to OpenSSL 3.6.3. - OpenSSL 4.0 users should upgrade to OpenSSL 4.0.1. - OpenSSL 1.1.1 and 1.0.2 are not affected. 4. Double-free When Checking OCSP Stapled Response (CVE-2026-35188) Vulnerability Overview: A malicious server can exploit TLS OCSP stapling by sending a forged response via the status request extension, triggering a double-free in the client certificate verification path. Affected Versions: - OpenSSL 4.0 and 3.0 are affected. - The FIPS module is not affected. Remediation: - OpenSSL 4.0 users should upgrade to OpenSSL 4.0.1. - OpenSSL 3.0 users should upgrade to OpenSSL 3.0.21. - OpenSSL 3.5, 3.4, 1.1.1, and 1.0.2 are not affected. 5. NULL Pointer Dereference in QUIC Server Initial Packet Handling (CVE-2026-42764) Vulnerability Overview: Receiving a QUIC initial packet with an invalid token may cause a NULL pointer dereference in the OpenSSL QUIC server. Affected Versions: - OpenSSL 4.0, 3.6, and 3.5 are affected. - The FIPS module is not affected. Remediation: - OpenSSL 4.0 users should upgrade to OpenSSL 4.0.1. - OpenSSL 3.6 users should upgrade to OpenSSL 3.6.3. - OpenSSL 3.5 users should upgrade to OpenSSL 3.5.7. - OpenSSL 3.4, 3.0, 1.1.1, and 1.0.2 are not affected. 6. AES-OCB IV Ignored on EVP_Cipher() Path (CVE-2026-45448) Vulnerability Overview: When an application drives an AES-OCB context through the public EVP_Cipher() one-shot interface, the application-provided initialization vector (IV) is silently discarded. Affected Versions: - OpenSSL 4.0, 3.6, 3.5, 3.4, and 3.0 are affected. - The FIPS module is not affected. Remediation: - OpenSSL 4.0 users should upgrade to OpenSSL 4.0.1. - OpenSSL 3.6 users should upgrade to OpenSSL 3.6.3. - OpenSSL 3.5 users should upgrade to OpenSSL 3.5.7. - OpenSSL 3.4 users should upgrade to OpenSSL 3.4.6. - OpenSSL 3.0 users should upgrade to OpenSSL 3.0.21. - OpenSSL 1.1.1 and 1.0.2 are not affected. 7. Possible Heap Buffer Overflow in ASN.1 Multibyte String Conversion (CVE-2026-7393) Vulnerability Overview: A signed integer overflow in ASN.1 multibyte string conversion can lead to a heap buffer overflow. Affected Versions: - OpenSSL 4.0, 3.6, 3.5, 3.4, 3.0, 1.1.1, and 1.0.2 are affected. - The FIPS module is not affected. Remediation: - OpenSSL 4.0 users should upgrade to OpenSSL 4.0.1. - OpenSSL 3.6 users should upgrade to OpenSSL 3.6.3. - OpenSSL 3.5 users should upgrade to OpenSSL 3.5.7. - OpenSSL 3.4 users should upgrade to OpenSSL 3.4.6. - OpenSSL 3.0 users should upgrade to OpenSSL 3.0.21. - OpenSSL 1.1.1 users should upgrade to OpenSSL 1.1.1h. - OpenSSL 1.0.2 users should upgrade to OpenSSL 1.0.2q. 8. Out-of-Bounds Read in CMS Password-Based Decryption (CVE-2026-9076) Vulnerability Overview: During CMS password-based decryption, an attacker-selected stream-mode KEK cipher can trigger an out-of-bounds read. Affected Versions: - OpenSSL 4.0, 3.6, 3.5, 3.4, 3.0, 1.1.1, and 1.0.2 are affected. - The FIPS module is not affected. Remediation: - OpenSSL 4.0 users should upgrade to OpenSSL 4.0.1. - OpenSSL 3.6

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OpenSSL Security Bulletin: 4 CVEs (UAF, CMS Forgery, DoS, Double-free) with Patch Versions