Inconsistent interpretation of HTTP requests in undici - CVE-2026-16728

 

Inconsistent interpretation of HTTP requests in undici - CVE-2026-16728

Published: July 29, 2026


Vulnerability identifier: #VU140034
CSH Severity: Medium
CVSS v4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-16728
CWE-ID: CWE-444
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to cause downstream response desynchronization, connection hangs, or response corruption.

The vulnerability exists due to inconsistent interpretation of HTTP response framing in interceptors.retry() when retrying or resuming a partial upstream response. A remote attacker can send a partial response with mismatched framing headers to cause downstream response desynchronization, connection hangs, or response corruption.

The issue requires interceptors.retry() to be enabled and a downstream forwarder that forwards upstream headers and bodies without removing or recalculating Content-Length.


Affected software

undici
IBM Maximo Application Suite
Netezza Appliance - Cyclops
Informix Dynamic Server

How to mitigate CVE-2026-16728

Install security update from vendor's website.

undici - addressed in versions 6.28.0, 7.29.0, 8.9.0
IBM Maximo Application Suite - addressed in versions 9.0.29, 9.1.21, 9.2.2
Netezza Appliance - Cyclops - update to 11.3.1.4
Informix Dynamic Server - addressed in versions 14.10.FC14W1, 15.0.1.16

External References

Related Security Bulletins