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Ubuntu Security NoticesUSN-8678-3

USN-8678-3: OpenSSL vulnerability

USN-8673-1 fixed vulnerabilities in OpenSSL. The update inadvertently left out the fix for CVE-2026-75803 in Ubuntu 26.04 LTS. This update fixes the problem. We apologize for the inconvenience. Original advisory details: It was discovered that OpenSSL incorrectly handled the QUIC server incoming channel queue. A remote attacker could possibly use this issue to cause OpenSSL to use excessive resources, leading to a denial of service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-14456) It was discovered that OpenSSL incorrectly handled signature algorithm selection when using Raw Public Keys. A remote attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-14457) It was discovered that OpenSSL incorrectly handled QUIC INITIAL packet processing. A remote attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-18798) It was discovered that OpenSSL incorrectly handled buffering of DTLS records for a future epoch. A remote attacker could possibly use this issue to cause OpenSSL to use excessive resources, leading to a denial of service. (CVE-2026-54874) It was discovered that OpenSSL incorrectly handled CMS key unwrapping. A remote attacker could possibly use this issue to cause a heap buffer overflow, leading to a denial of service or arbitrary code execution. (CVE-2026-63072) It was discovered that OpenSSL incorrectly validated the sender distinguished name in CMP response messages. A remote attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-63073) It was discovered that OpenSSL incorrectly limited the growth of an internal certificate cache used during CMP operations. A remote attacker could possibly use this issue to cause OpenSSL to use excessive resources, leading to a denial of service. (CVE-2026-63074) It was discovered that OpenSSL incorrectly handled QUIC ACK-only packet retention. A remote attacker could possibly use this issue to cause OpenSSL to use excessive resources, leading to a denial of service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-63075) It was discovered that OpenSSL incorrectly handled CMP protection algorithm validation. A remo

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Scope

What the vendor says is affected

The collected bulletin did not provide a separate affected-products list. Check the original bulletin before making an exposure decision.

Next step

What the vendor recommends

USN-8673-1 fixed vulnerabilities in OpenSSL.

Review the complete instructions on the vendor's site
Timeline

When this advisory changed

  1. Published by Ubuntu

    The publication date reported by the vendor.

  2. Added to SecurityAlert

    We collected the advisory from the official source.

  3. Confirmed at the source

    Our collector saw this advisory during a later source check.

Vulnerabilities

CVEs named in this advisory