CVE-2026-65100 MEDIUM

CVE-2026-65100: Apache Traffic Server: HPACK encoder desynchronizes from the decoder after a failed header encode

Vendor Apache Software Foundation
Product Apache Traffic Server
Weakness CWE-696
Published July 29, 2026
Last update July 29, 2026
View on NVD All CVEs

CVSS base score

4.8/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality None
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

July 29, 2026 CVE published