HIGH8.7

GHSA-3gv6-g396-9v4r

Undertow is Vulnerable to HTTP Request/Response Smuggling

Details

A flaw was found in Undertow. A remote attacker can exploit this vulnerability by sending `\r\r\r` as a header block terminator. This can be used for request smuggling with certain proxy servers, such as older versions of Apache Traffic Server and Google Cloud Classic Application Load Balancer, potentially leading to unauthorized access or manipulation of web requests.

Are you affected?

Enter the version of the package you're using.

Affected packages

Maven/io.undertow:undertow-parent

Introduced in: 0

No fixed version published yet for io.undertow:undertow-parent (maven). Pin to a known-safe version or switch to an alternative.

References

https://nvd.nist.gov/vuln/detail/CVE-2026-28367[ADVISORY]
https://access.redhat.com/errata/RHSA-2026:25125[WEB]
https://access.redhat.com/errata/RHSA-2026:25126[WEB]
https://access.redhat.com/security/cve/CVE-2026-28367[WEB]
https://bugzilla.redhat.com/show_bug.cgi?id=2443260[WEB]
https://github.com/undertow-io/undertow[PACKAGE]