What is CVE-2026-65100?

CVE-2026-65100 is a medium-severity vulnerability in Apache Traffic Server, classified under CWE-696. CVSS score: 4.8/10. Published 2026-07-29.

How severe is CVE-2026-65100?

Medium severity. CVSS v3 base score is 4.8 out of 10.

Vulnerability in Apache Traffic Server

CVE-2026-65100

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.

EPSS: 0.004 (28.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L.

Affected products

Apache Traffic_server
Apache Software Foundation Traffic Server — versions 8.0.0, 9.0.0, 10.0.0

Weakness classification (CWE)

CWE-696

References

security@apache.org (vendor-advisory, Mailing List, Vendor Advisory)

Frequently asked questions

What is CVE-2026-65100?: CVE-2026-65100 is a medium-severity vulnerability in Apache Traffic Server, classified under CWE-696. CVSS score: 4.8/10. Published 2026-07-29.
How severe is CVE-2026-65100?: Medium severity. CVSS v3 base score is 4.8 out of 10.