Mend.io Vulnerability Database
The largest open source vulnerability database
What is a Vulnerability ID?
New vulnerability? Tell us about it!
CVE-2026-18149
Published:September 04, 2026
Updated:September 13, 2026
undici's retry handler can leave an already-exposed response body pending forever. When a server returns a successful response that declares a Content-Length, sends only part of the body, and closes the connection, the retry handler retries the request. If the retry returns a non-retryable status such as 400, the handler forwards that new response downstream and replaces its internal response stream, but the original response body that the application still holds is never ended or destroyed. As a result calls that read that body never settle, and the configured body timeout does not fire because its timer is tied to the connection parser rather than the orphaned body. An attacker-controlled server can trigger this with two short responses without keeping a connection open, and repeated requests accumulate pending promises and streams that can exhaust application concurrency or memory. This affects undici versions from 7.11.0 up to 7.29.1 and from 8.0.0 up to 8.10.2. Users should upgrade to undici 7.29.1 or 8.10.2.
Affected Packages
https://github.com/nodejs/undici.git (GITHUB):
Affected version(s) >=v7.11.0 <v7.29.1
Fix Suggestion:
Update to version v7.29.1
https://github.com/nodejs/undici.git (GITHUB):
Affected version(s) >=v8.0.0 <v8.10.2
Fix Suggestion:
Update to version v8.10.2
undici (NPM):
Affected version(s) >=8.0.0 <8.10.2
Fix Suggestion:
Update to version 8.10.2
undici (NPM):
Affected version(s) >=7.11.0 <7.29.1
Fix Suggestion:
Update to version 7.29.1
Do you need more information?
Contact Us
CVSS v4
Base Score:
8.2
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
5.9
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Missing Release of Resource after Effective Lifetime
EPSS
Base Score:
0.31