Apache Traffic Server up to 8.1.11/9.2.15/10.1.4/10.2.0 certificate validation

Summaryinfo

A vulnerability labeled as problematic has been found in Apache Traffic Server up to 8.1.11/9.2.15/10.1.4/10.2.0. The affected element is an unknown function. The manipulation results in certificate validation. This vulnerability is known as CVE-2026-111815. It is possible to launch the attack remotely. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as problematic has been found in Apache Traffic Server up to 8.1.11/9.2.15/10.1.4/10.2.0. Affected is an unknown part. The manipulation with an unknown input leads to a certificate validation vulnerability. CWE is classifying the issue as CWE-295. The product does not validate, or incorrectly validates, a certificate. This is going to have an impact on integrity. CVE summarizes:

Apache Traffic Server can resume a TLS session across SNI virtual hosts without re-verifying a client certificate required by the resumed host's verify_client STRICT policy. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0. Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.

The advisory is shared for download at lists.apache.org. This vulnerability is traded as CVE-2026-111815 since 10/16/2026. The exploitability is told to be difficult. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 10/21/2026). The MITRE ATT&CK project declares the attack technique as T1587.003.

Upgrading to version 9.2.16, 10.1.5 or 10.2.1 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-107500). Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• Apache

Name

• Traffic Server

Version

• 8.1.0
• 8.1.1
• 8.1.2
• 8.1.3
• 8.1.4
• 8.1.5
• 8.1.6
• 8.1.7
• 8.1.8
• 8.1.9
• 8.1.10
• 8.1.11
• 9.2.0
• 9.2.1
• 9.2.2
• 9.2.3
• 9.2.4
• 9.2.5
• 9.2.6
• 9.2.7
• 9.2.8
• 9.2.9
• 9.2.10
• 9.2.11
• 9.2.12
• 9.2.13
• 9.2.14
• 9.2.15
• 10.0
• 10.1
• 10.1.0
• 10.1.1
• 10.1.2
• 10.1.3
• 10.1.4
• 10.2.0

License

• open-source

Website

• Vendor: https://www.apache.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Once again VulDB remains the best source for vulnerability data.

Discussion