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 p

mediumCVSS 4.8CVE-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.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: medium — CVSS 4.8
Published: 2026-07-29
Last updated: 2026-07-30
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-65100

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-651000.25% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 17% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-65100	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

high[NEW] [high] Apache Traffic Server: Multiple vulnerabilitiescert-bund

Recent advisories for Apache Traffic Server

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

high[NEW] [high] Apache Traffic Server: Multiple vulnerabilitiescert-bund · 2026-07-30
highCVE-2026-58189: Apache Traffic Server allows redirect-limit bypass when plugins reset the retry counter, enabl…nvd · 2026-07-29
highCVE-2026-58188: Several Apache Traffic Server experimental plugins have memory-safety and limit-bypass errors.…nvd · 2026-07-29
lowCVE-2026-58187: The Apache Traffic Server multiplexer plugin overruns its chunk-decode buffer on upstream inpu…nvd · 2026-07-29
highCVE-2026-58186: The Apache Traffic Server webp_transform plugin can decode unsafely and serve mislabeled, cach…nvd · 2026-07-29
mediumCVE-2026-58185: The Apache Traffic Server intercept plugin has a use-after-free. This issue affects Apache Tra…nvd · 2026-07-29