OpenSSL Security Bulletin: Fixes for RCE, Heap Overflow, and DoS Vulnerabilities

1. QUIC Server May Trigger Double Free When Processing INITIAL Packet (CVE-2026-19798) Vulnerability Overview: The QUIC server may trigger a double-free vulnerability when processing INITIAL packets. Affected Versions: OpenSSL 4.0, 3.6, 3.5, 3.4, 1.1.1, and 1.0.2 are affected. Remediation: - Users of OpenSSL 4.0 should upgrade to version 4.0.2. - Users of OpenSSL 3.6 should upgrade to version 3.6.4. - Users of OpenSSL 3.5 should upgrade to version 3.5.8. - Users of OpenSSL 3.4 should upgrade to version 3.4.7. - Users of OpenSSL 3.0 should upgrade to version 3.0.22. 2. Heap Buffer Overflow in CMS Key Unwrapping (CVE-2026-63072) Vulnerability Overview: An attacker can trigger a heap buffer overflow by providing a malicious CMS message, leading to a denial of service. Affected Versions: OpenSSL 4.0, 3.6, 3.5, 3.4, 3.0, and 1.1.1 are affected. Remediation: - Users of OpenSSL 4.0 should upgrade to version 4.0.2. - Users of OpenSSL 3.6 should upgrade to version 3.6.4. - Users of OpenSSL 3.5 should upgrade to version 3.5.8. - Users of OpenSSL 3.4 should upgrade to version 3.4.7. - Users of OpenSSL 3.0 should upgrade to version 3.0.22. 3. Invalid Pointer Dereference in CMP Server via Crafted protectionAlgo (CVE-2026-63076) Vulnerability Overview: An attacker can cause a null pointer dereference via a crafted parameter, resulting in a denial of service. Affected Versions: OpenSSL 4.0, 3.6, 3.5, 3.4, and 3.0 are affected. Remediation: - Users of OpenSSL 4.0 should upgrade to version 4.0.2. - Users of OpenSSL 3.6 should upgrade to version 3.6.4. - Users of OpenSSL 3.5 should upgrade to version 3.5.8. - Users of OpenSSL 3.4 should upgrade to version 3.4.7. - Users of OpenSSL 3.0 should upgrade to version 3.0.22. 4. RPK Server Signature Algorithm Selection Can Dereference a Missing Certificate (CVE-2026-14457) Vulnerability Overview: Under specific configurations, the server may trigger a null pointer dereference due to a missing certificate, causing a denial of service. Affected Versions: OpenSSL 4.0, 3.6, 3.5, and 3.4 are affected. Remediation: - Users of OpenSSL 4.0 should upgrade to version 4.0.2. - Users of OpenSSL 3.6 should upgrade to version 3.6.4. - Users of OpenSSL 3.5 should upgrade to version 3.5.8. - Users of OpenSSL 3.4 should upgrade to version 3.4.7. 5. Excessive Memory Use Buffering DTLS Records for a Future Epoch (CVE-2026-54874) Vulnerability Overview: Receiving DTLS records for a future epoch can lead to abnormal memory usage, resulting in a denial of service. Affected Versions: OpenSSL 4.0, 3.6, 3.5, 3.4, 3.0, 1.1.1, and 1.0.2 are affected. Remediation: - Users of OpenSSL 4.0 should upgrade to version 4.0.2. - Users of OpenSSL 3.6 should upgrade to version 3.6.4. - Users of OpenSSL 3.5 should upgrade to version 3.5.8. - Users of OpenSSL 3.4 should upgrade to version 3.4.7. - Users of OpenSSL 3.0 should upgrade to version 3.0.22. 6. Untrusted Sender DN Used as Format String in CMP Response Validation (CVE-2026-63073) Vulnerability Overview: Using an untrusted sender DN as a format string can lead to a denial of service. Affected Versions: OpenSSL 4.0, 3.6, 3.5, and 3.4 are affected. Remediation: - Users of OpenSSL 4.0 should upgrade to version 4.0.2. - Users of OpenSSL 3.6 should upgrade to version 3.6.4. - Users of OpenSSL 3.5 should upgrade to version 3.5.8. - Users of OpenSSL 3.4 should upgrade to version 3.4.7. 7. CMP Indefinite Cache Growth of ExtraCerts (CVE-2026-63074) Vulnerability Overview: Unlimited growth of extra certificates in the CMP protocol can lead to a denial of service. Affected Versions: OpenSSL 4.0, 3.6, 3.5, 3.4, and 3.0 are affected. Remediation: - Users of OpenSSL 4.0 should upgrade to version 4.0.2. - Users of OpenSSL 3.6 should upgrade to version 3.6.4. - Users of OpenSSL 3.5 should upgrade to version 3.5.8. - Users of OpenSSL 3.4 should upgrade to version 3.4.7. - Users of OpenSSL 3.0 should upgrade to version 3.0.22. 8. QUIC ACK-only Packet Retention Can Cause Memory Exhaustion (CVE-2026-63075) Vulnerability Overview: Retention of ACK-only packets in the QUIC protocol can lead to memory exhaustion. Affected Versions: OpenSSL 4.0, 3.6, 3.5, and 3.4 are affected. Remediation: - Users of OpenSSL 4.0 should upgrade to version 4.0.2. - Users of OpenSSL 3.6 should upgrade to version 3.6.4. - Users of OpenSSL 3.5 should upgrade to version 3.5.8. - Users of OpenSSL 3.4 should upgrade to version 3.4.7. 9. AEAD Forgeries with Empty Ciphertext When Using EVP_Cipher() (CVE-2026-75883) Vulnerability Overview: Using with empty ciphertext can lead to AEAD forgeries, causing a denial of service. Affected Versions: OpenSSL 4.0, 3.6, 3.5, 3.4, and 3.0 are affected. Remediation: - Users of OpenSSL 4.0 should upgrade to version 4.0.2. - Users of OpenSSL 3.6 should upgrade to version 3.6.4. - Users of OpenSSL 3.5 should upgrade to version 3.5.8. - Users of OpenSSL 3.4 should upgrade to version 3.4.7. - Users of OpenSSL 3.0 should upgrade to version 3.0.22. Summary Vulnerability Overview: Mult

Goal Reached Thanks to every supporter — we hit 100%!

OpenSSL Security Bulletin: Fixes for RCE, Heap Overflow, and DoS Vulnerabilities