CVE-2026-65100

MEDIUM

Apache Traffic Server: HPACK encoder desynchronizes from the decoder after a failed header encode

Title source: CVE List
STIX 2.1 vulnerability

Record summary

CVE-2026-65100 has a selected CVSS score of 6.3 (medium).

Description

Apache Traffic Server updates the HTTP/2 HPACK dynamic table before confirming the header block encoded successfully, so an encode failure leaves the encoder out of sync with the peer decoder and corrupts subsequent header blocks on the connection. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.9, from 9.0.0 through 9.2.14, from 10.0.0 through 10.1.3. Users are recommended to upgrade to version 9.2.15 or 10.1.4, which fix the issue.

Description source: CVE List

Exploitation context

CISA SSVC decision

ExploitationNone
AutomatableNo
Technical impactPartial

CISA Coordinator · SSVC 2.0.3 · Evaluated Jul 29, 2026 · Source: CVE List

Affected products and versions

1
ProductSourceVersion range

Apache Traffic Server

Browse Apache Software Foundation / Apache Traffic Server

Default status: unaffected

CVE List8.0.0 to ≤ 8.1.9affected
9.0.0 to ≤ 9.2.14affected
10.0.0 to ≤ 10.1.3affected

References

2