CVE-2026-19879
Last modified
CVE-2026-19879 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. 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.
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.
Metrics
Weakness Enumeration
Affected Software
Source: CNA advisory (CVE.org). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| Red Hat | Red Hat build of Apache Camel for Spring Boot 4 | All versions |
| Red Hat | Red Hat Enterprise Linux 10 | All versions |
| Red Hat | Red Hat Enterprise Linux 8 | All versions |
| Red Hat | Red Hat Enterprise Linux 9 | All versions |
| Red Hat | Red Hat JBoss Enterprise Application Platform 7 | All versions |
| Red Hat | Red Hat JBoss Enterprise Application Platform 8 | All versions |
| Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | All versions |
| Red Hat | Red Hat Single Sign-On 7 | All versions |
References
Timeline
- Published
- Last Modified
- Status
- Awaiting Analysis
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How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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