All vulnerabilities
CVE-2025-31699

Apache Traffic Server: Origin connection still owed a request body is reused, enabling request smuggling

Apache Software Foundation Apache Traffic Server
Open in ThreatlineRecord JSON
CVSS
8.9High
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.27%Chance of exploitation activity in the next 30 days, higher than 17% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Published21 Oct 2026Updated 23 Oct 2026CVE List

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

Description

Apache Traffic Server can return an origin connection to the shared pool while the origin is still waiting on a request body the client declared but never fully sent, including when the client used Expect: 100-continue. The origin then reads a later request on that connection as leftover body data, which lets an attacker smuggle requests past ATS access controls, disrupt other users' requests, or poison the cache.

This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0.

Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.

Text from CVE List

Affected versions 4

  • Apache Traffic Serveraffected: 8.0.0 through 8.1.11CVE List
  • Apache Traffic Serveraffected: 9.0.0 through 9.2.15CVE List
  • Apache Traffic Serveraffected: 10.0.0 through 10.1.4CVE List
  • Apache Traffic Serveraffected: 10.2.0CVE List

References 1