CVE-2025-31699: Apache Traffic Server · HTTP Request Smuggling
Affects Apache Traffic ServerSource CVE Database V5
Not known to be exploited · CVSS 8.9 High.
Data as of 29 Oct 2026, 18:50 UTC
Thin evidence
One scorer or none| CNA (apache) | CVSS 3.1 | 8.9 |
|---|---|---|
| CNA (apache) | CVSS 4.0 | 9.1 |
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 28% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:LExploitation evidence
Disclosed: evidence found.
CVE published 21 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Apache Software FoundationApache Traffic Server | Affected
| Fixed in– |
AI-suggested
Users should upgrade Apache Traffic Server to versions 9.2.16, 10.1.5, or 10.2.1, which contain fixes for this vulnerability. No other mitigations are specified by the vendor advisory.
Description
CVE-2025-31699 is a high-severity HTTP request/response smuggling vulnerability in Apache Traffic Server. It occurs when the server returns an origin connection to the shared pool while the origin is still waiting on a request body that the client declared but never fully sent, including cases using Expect: 100-continue. This allows the origin to misinterpret subsequent requests as leftover body data, enabling attackers to smuggle requests past access controls, disrupt other users' requests, or poison the cache. The issue affects multiple versions from 8.0.0 through 8.1.11, 9.0.0 through 9.2.15, 10.0.0 through 10.1.4, and version 10.2.0. Fixed versions are 9.2.16, 10.1.5, and 10.2.1.