Is CVE-2026-111817 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-111817 being exploited in the wild.

How severe is CVE-2026-111817?

Medium severity, with a CVSS score of 5.3, published 21 October 2026.

Which products and versions are affected?

Apache Traffic Server 8.1.11, 9.2.5–9.2.15, 10.0.0–10.1.4, 10.2.0.

Is there a fix for CVE-2026-111817?

Yes: fixed in 10.1.5, 10.2.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-111817 attacked?

It is attacked over the network, in a web application.

Am I affected by CVE-2026-111817?

Check whether you run Apache Traffic Server at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-111817: Apache Traffic Server connection stall with chunked transfer trailers dropped

CVE-2026-111817 · Severity: medium · CVSS 5.3 · Published 2026-10-21

Apache Traffic Server is a reverse proxy and caching server that forwards web traffic. When configured to drop trailers from chunked transfers, it can stall indefinitely waiting for trailer bytes it has already discarded, causing the connection to hang until it times out. This affects deployments that have enabled trailer dropping, which is on by default in version 10.x.

Technologies: Apache Traffic Server. Vendors: Apache.

Quick answers

Is CVE-2026-111817 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-111817 being exploited in the wild.
How severe is CVE-2026-111817?: Medium severity, with a CVSS score of 5.3, published 21 October 2026.
Which products and versions are affected?: Apache Traffic Server 8.1.11, 9.2.5–9.2.15, 10.0.0–10.1.4, 10.2.0.
Is there a fix for CVE-2026-111817?: Yes: fixed in 10.1.5, 10.2.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-111817 attacked?: It is attacked over the network, in a web application.
Am I affected by CVE-2026-111817?: Check whether you run Apache Traffic Server at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: 10.1.5, 10.2.1

Technical details

The vulnerability occurs in HTTP/1.1 chunked transfer encoding handling when proxy.config.http.drop_chunked_trailers is enabled. The server drops trailer headers but continues waiting for the trailer bytes on the wire, causing a stall. The issue affects versions 8.1.11, 9.2.5–9.2.15, and 10.0.0–10.1.4, with trailer dropping on by default in 10.x but off by default in earlier versions.

Affected products

Apache Traffic Server 8.1.11, 9.2.5–9.2.15, 10.0.0–10.1.4, 10.2.0

Timeline

2026-10-21: disclosed

References

https://lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kc

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