CVE-2026-111811 Apache Software Foundation CVE debrief

Who should care

Defenders responsible for Apache Traffic Server deployments should assess exposure and prioritize upgrading to patched versions to prevent potential cache manipulation. This includes operators, platform administrators, vulnerability management teams, and security teams. They should review the official advisory and CVE record to validate affected scope, severity, and vendor guidance. Defenders should also monitor Apache Traffic Server deployments for signs

Why it matters

Apache Traffic Server's tsmemcache plugin vulnerability allows unauthenticated network access to the shared proxy cache, enabling read, write, and deletion operations. Defenders should prioritize upgrading to patched versions to prevent potential cache manipulation.

• Potential cache manipulation through unauthenticated network access
• Possible data tampering or unauthorized cache modifications
• Risk of cache poisoning or denial of service
• Need for verification of affected versions and exposure

Technical summary

Apache Traffic Server's experimental tsmemcache plugin allows unauthenticated network read, write, and deletion of the shared proxy cache. This issue affects Apache Traffic Server versions from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, and 10.2.0. The vulnerability could lead to potential cache manipulation, data tampering, or unauthorized cache modifications. Defenders should prioritize upgrading to patched versions to prevent these risks. The tsmemcache plugin's vulnerability has been publicly disclosed, and defenders should review the official advisory for further information.

Defensive priority

Defenders should prioritize upgrading to patched versions of Apache Traffic Server to prevent potential cache manipulation.

Recommended defensive actions

• Upgrade to Apache Traffic Server version 9.2.16, 10.1.5, or 10.2.1
• Review and update affected versions of Apache Traffic Server
• Monitor Apache Traffic Server deployments for potential cache manipulation
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record and source item provide details on the vulnerability in Apache Traffic Server's tsmemcache plugin. The issue allows unauthenticated network access to the shared proxy cache. Evidence is limited to the CVE record and source item, and defenders should verify affected versions and exposure. The tsmemcache plugin's vulnerability has been publicly disclosed, and defenders should review the official advisory for further information.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.