GHSA-vqqj-9cmv-hx43
Undertow is Vulnerable to HTTP Request/Response Smuggling
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| Maven | io.undertow:undertow-core | < 2.2.40.Final | 2.2.40.Final |
| Maven | io.undertow:undertow-core | >= 2.3.0.Final, < 2.3.25.Final | 2.3.25.Final |
Details
As written in the advisory (Markdown source, shown as plain text).
A flaw was found in Undertow. When Undertow receives an HTTP request where the first header line starts with one or more spaces, it incorrectly processes the request by stripping these leading spaces. This behavior, which violates HTTP standards, can be exploited by a remote attacker to perform request smuggling. Request smuggling allows an attacker to bypass security mechanisms, access restricted information, or manipulate web caches, potentially leading to unauthorized actions or data exposure.
References
External links from the advisory. They lead to third-party sites.
- https://nvd.nist.gov/vuln/detail/CVE-2026-28369
- https://github.com/undertow-io/undertow/commit/3ece0bf2b2cf5e01db8ca25e41b831e66d3f5961
- https://github.com/undertow-io/undertow/commit/904e26f1be62fb00b440538608a9574839821878
- https://github.com/undertow-io/undertow/commit/c5dc41479e9c3576552d7e98e31bb1c237ae155e
- https://access.redhat.com/errata/RHSA-2026:25125
- https://access.redhat.com/errata/RHSA-2026:25126
- https://access.redhat.com/security/cve/CVE-2026-28369
- https://bugzilla.redhat.com/show_bug.cgi?id=2443262
- https://github.com/undertow-io/undertow