CVE-2026-19879 Io.undertow/undertow: undertow: http response header integrity issue due to character truncation
Description
A flaw was found in Undertow, an HTTP server, within its HTTP response header writing path. The `writeString()` method performs a silent narrowing cast from 16-bit Unicode characters to 8-bit bytes when writing HTTP response header values. A remote attacker can exploit this by supplying specific Unicode characters in user-controlled input that an application places into response headers. This can lead to the truncation of these characters into ASCII control characters or special symbols, potentially resulting in limited integrity impact or information disclosure if the application does not properly sanitize user input.
CVSS 3.1 detail
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:NExploitable remotely over the network, without an account and without any user action; the impact on data or service is limited.
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- Interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Red Hat build of Apache Camel for Spring Boot 4 | Versions not published | |
| Red Hat Enterprise Linux 10 | Versions not published | |
| Red Hat Enterprise Linux 8 | Versions not published | |
| Red Hat Enterprise Linux 9 | Versions not published | |
| Red Hat JBoss Enterprise Application Platform 7 | Versions not published | |
| Red Hat JBoss Enterprise Application Platform 8 | Versions not published | |
| Red Hat JBoss Enterprise Application Platform Expansion Pack | Versions not published | |
| Red Hat Single Sign-On 7 | Versions not published |
References
- access.redhat.com access.redhat.com
- RHBZ#2516038 bugzilla.redhat.com
Timeline
- Published
- Last modified