Vulnerability · Published Mar 27, 2026 · Assigned by redhat
CVE-2026-28367Undertow: undertow: request smuggling via `\r\r\r` as a header block terminator
High 8.7
In plain English
A high-severity security flaw in Red Hat build of Apache Camel for Spring Boot 4 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 54% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:14 | undertow | no fix listed | DEBIAN-CVE-2026-28367 |
| Maven | io.undertow:undertow-core | 2.3.25.Final | GHSA-3gv6-g396-9v4r |
| Maven | io.undertow:undertow-core | 2.2.40.Final | GHSA-3gv6-g396-9v4r |
| Ubuntu:25.10 | undertow | no fix listed | UBUNTU-CVE-2026-28367 |
| Ubuntu:26.04:LTS | undertow | no fix listed | UBUNTU-CVE-2026-28367 |
| Ubuntu:26.10 | undertow | no fix listed | UBUNTU-CVE-2026-28367 |
Affected products (as reported)
Weakness: CWE-444 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N
References
- RHSA-2026:25125 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:25126 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-28367 vdb-entry, x_refsource_REDHAT
- RHBZ#2443260 issue-tracking, x_refsource_REDHAT