Apache Traffic Server up to 8.1.11/9.2.15/10.1.4/10.2.0 request smuggling

Summaryinfo

A vulnerability was found in Apache Traffic Server up to 8.1.11/9.2.15/10.1.4/10.2.0. It has been rated as problematic. This vulnerability affects unknown code. Performing a manipulation results in request smuggling. This vulnerability is reported as CVE-2026-111809. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Apache Traffic Server up to 8.1.11/9.2.15/10.1.4/10.2.0. It has been classified as problematic. This affects an unknown function. The manipulation with an unknown input leads to a request smuggling vulnerability. CWE is classifying the issue as CWE-444. The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination. This is going to have an impact on integrity. The summary by CVE is:

Apache Traffic Server allows request smuggling via HEAD requests that carry Content-Length or Transfer-Encoding. 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 at lists.apache.org. This vulnerability is uniquely identified as CVE-2026-111809 since 10/16/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/21/2026).

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-2026-107503). Several companies clearly confirm that VulDB is the primary source for best 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/

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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