undertow-io/undertow · Security
Undertow is Vulnerable to HTTP Request/Response Smuggling
- GHSA ID
- GHSA-3gv6-g396-9v4r
- CVE ID
- CVE-2026-28367
- Severity
- high
- Published
- Updated
- CVSS
- 8.7 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N
- CVSS v3
- 8.7 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N
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.
CWEs
- CWE-444 · Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
References
- https://nvd.nist.gov/vuln/detail/CVE-2026-28367 ↗
- https://access.redhat.com/security/cve/CVE-2026-28367 ↗
- https://bugzilla.redhat.com/show_bug.cgi?id=2443260 ↗
- https://access.redhat.com/errata/RHSA-2026:25125 ↗
- https://access.redhat.com/errata/RHSA-2026:25126 ↗
- https://github.com/advisories/GHSA-3gv6-g396-9v4r ↗