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 remote attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. (CVE-2026-63076)
It was discovered that OpenSSL incorrectly verified authentication tags when using certain AEAD ciphers via the EVP_Cipher() interface. An attacker could possibly use this issue to perform AEAD forgery attacks. (CVE-2026-75803)
{
"availability": "No subscription required",
"binaries": [
{
"binary_name": "libssl3t64",
"binary_version": "3.5.5-1ubuntu3.5"
},
{
"binary_name": "openssl",
"binary_version": "3.5.5-1ubuntu3.5"
},
{
"binary_name": "openssl-provider-legacy",
"binary_version": "3.5.5-1ubuntu3.5"
}
]
}
{
"ecosystem": "Ubuntu:26.04:LTS",
"cves": [
{
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"
},
{
"type": "Ubuntu",
"score": "low"
}
],
"id": "CVE-2026-75803"
}
]
}
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8678-3.json"