Summary
CVE-2026-58162 is a critical improper certificate validation vulnerability (CWE-295) in the certifier plugin of Apache Traffic Server. The plugin generates TLS certificates based on the attacker-controlled client SNI (Server Name Indication) value, allowing a remote, unauthenticated attacker to influence certificate generation over the network. It carries a CVSS v3.1 base score of 10.0 (Critical).
Technical details
- Root cause: The Apache Traffic Server certifier plugin generates certificates using the SNI value supplied by the client, which is attacker-controlled, resulting in improper certificate validation (CWE-295).
- Trigger conditions: A deployment must be running the certifier plugin; an attacker sends a TLS request with a crafted SNI value to drive certificate generation.
- Attack vector: Network (AV:N), low attack complexity, no privileges and no user interaction required.
- Impact: Compromise of the certificate generation process, undermining the trust and integrity of TLS certificates served by the proxy (High integrity and availability impact, Low confidentiality impact per the CVSS vector).
Affected software
- Apache Traffic Server 8.0.0 through 8.1.9
- Apache Traffic Server 9.0.0 through 9.2.14
- Apache Traffic Server 10.0.0 through 10.1.3
Severity
- CVSS v3.1 base score: 10.0 (Critical)
- Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:H - The vendor also assigned a CVSS v4.0 base score of 8.4 (
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N).
Mitigation and recommended actions
- Immediate: Upgrade to a fixed release — Apache Traffic Server 9.2.15 or 10.1.4 (or later). Users on the 8.x branch should upgrade to a supported, fixed release.
- If no patch: Where an immediate upgrade is not possible, avoid using the certifier plugin, which is the component affected by this vulnerability.

