# CVE-2026-111804: Apache Traffic Server use-after-free and metric ID validation bypass in wasm plugin

Source: https://junglewise.ai/threats/cve-2026-111804-apache-traffic-server-s-experimental-wasm-plugin-has-a-use-after  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-21. Updated: 2026-10-21  
License: CC BY 4.0 with a link back

CVE-2026-111804 · Severity: high · CVSS 8.2 · Published 2026-10-21

Apache Traffic Server is a caching proxy that manages web traffic for content delivery. The experimental WebAssembly plugin contains two flaws: a memory safety bug that can cause crashes or code execution, and a validation bypass that allows malicious metric IDs to corrupt internal statistics. An attacker could exploit these to disrupt service or inject false monitoring data.

Technologies: [Apache Traffic Server](https://junglewise.ai/threats/technologies/traffic-server). Vendors: [Apache](https://junglewise.ai/threats/vendors/apache).

## Quick answers

**Is CVE-2026-111804 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-111804 being exploited in the wild.

**How severe is CVE-2026-111804?** High severity, with a CVSS score of 8.2, published 21 October 2026.

**Which products and versions are affected?** Apache Traffic Server 10.0.0 through 10.1.4, 10.2.0.

**Is there a fix for CVE-2026-111804?** Yes: fixed in Traffic Server 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-2026-111804 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-111804?** 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 Traffic Server 10.1.5, 10.2.1

## Technical details

The vulnerability involves a use-after-free condition in the wasm plugin's transaction-close handler and insufficient validation of guest-supplied metric IDs passed to the internal stats API. The use-after-free can lead to memory corruption or arbitrary code execution, while the metric ID bypass allows injection of unvalidated values into the statistics subsystem. Both issues are reachable via network traffic processed by the wasm plugin.

## Affected products

- Apache Traffic Server 10.0.0 through 10.1.4, 10.2.0

## Timeline

- 2026-10-21: disclosed

## References

- [https://lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kc](https://lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kc)

## Related threats

- [Apache Traffic Server null pointer dereference in request tear-down](https://junglewise.ai/threats/cve-2026-112381-apache-traffic-server-can-crash-with-a-null-pointer-dereference)
- [Apache Traffic Server connection stall with chunked transfer trailers dropped](https://junglewise.ai/threats/cve-2026-111817-apache-traffic-server-can-stall-a-chunked-transfer-that-it)
- [Apache Traffic Server TLS session resumption bypass of client certificate verification](https://junglewise.ai/threats/cve-2026-111815-apache-traffic-server-can-resume-a-tls-session-across-sni)
- [Apache Traffic Server TLS session reuse with mismatched client certificates](https://junglewise.ai/threats/cve-2026-111814-apache-traffic-server-s-default-outbound-session-sharing-policy)
- [Apache Traffic Server origin_server_auth AWS request signing bypass](https://junglewise.ai/threats/cve-2026-111812-apache-traffic-server-s-origin-server-auth-plugin-lets-a-client)