CVE-2025-31699

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

HIGH
8.9
CVSS Score
Published: October 21, 2026 at 06:22 PM UTC
Updated: October 23, 2026 at 12:18 PM UTC
1 product affected across 1 vendorTraffic Server

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Severity
HIGH8.9
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.9HIGHapache
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
LOW
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-444

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