# CVE-2026-65100: Apache Traffic Server HTTP/2 HPACK dynamic table corruption

Source: https://junglewise.ai/threats/cve-2026-65100-apache-traffic-server-http-2-hpack-dynamic-table-corruption  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-29. Updated: 2026-07-29  
License: CC BY 4.0 with a link back

CVE-2026-65100 · Severity: medium · CVSS 4.8 · Published 2026-07-29

Apache Traffic Server, a high-performance web proxy used to manage and speed up internet traffic, contains a flaw in how it handles encrypted web headers. An attacker could potentially cause the system to lose synchronization with connected users, leading to corrupted data transfers. This results in a denial of service for specific web connections, impacting the reliability of the service for affected users.

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

## Quick answers

**Is CVE-2026-65100 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-65100 being exploited in the wild.

**How severe is CVE-2026-65100?** Medium severity, with a CVSS score of 4.8, published 29 July 2026.

**Which products and versions are affected?** Apache Traffic Server 8.0.0 through 8.1.9, 9.0.0 through 9.2.14, 10.0.0 through 10.1.3.

**Is there a fix for CVE-2026-65100?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-65100 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-65100?** 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.

## Technical details

A synchronization vulnerability exists in Apache Traffic Server's HTTP/2 implementation. The HPACK encoder updates its dynamic table state before verifying that the header block was successfully encoded. If an encoding failure occurs, the encoder's state becomes desynchronized from the peer decoder's state. This desynchronization results in the corruption of all subsequent header blocks on that specific connection. The issue is resolved in versions 9.2.15 and 10.1.4.

## Affected products

- Apache Traffic Server 8.0.0 through 8.1.9, 9.0.0 through 9.2.14, 10.0.0 through 10.1.3

## Timeline

- 2026-07-29: disclosed
- 2026-07-29: advisory

## References

- [https://lists.apache.org/thread/5prl9glcm9g2swnq9hqxvnokylm1gr6d](https://lists.apache.org/thread/5prl9glcm9g2swnq9hqxvnokylm1gr6d)

## 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)