CVE-2026-58150: Apache Traffic Server does not reject Transfer-Encoding in HTTP/2 requests, allowing downgrade request smuggling. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.

criticalCVSS 10CVE-2026-58150

Apache Traffic Server does not reject Transfer-Encoding in HTTP/2 requests, allowing downgrade request smuggling. 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: critical — CVSS 10
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-2026-58150

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-2026-581500.24% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 16% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-58150	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
mediumCVE-2026-65100: Apache Traffic Server updates the HTTP/2 HPACK dynamic table before confirming the header bloc…nvd · 2026-07-29
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