CVE-2026-4437
Last modified
CVE-2026-4437 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Calling gethostbyaddr or gethostbyaddr_r with a configured nsswitch.conf that specifies the library's DNS backend in the GNU C Library version 2.34 to version 2.43 could, with a crafted response from the configured DNS server, result in a violation of the DNS specification that causes the application to treat a non-answer section of the DNS response as a valid answer.. EPSS estimates a 0.29% chance of exploitation in the next 30 days.
Description
Calling gethostbyaddr or gethostbyaddr_r with a configured nsswitch.conf that specifies the library's DNS backend in the GNU C Library version 2.34 to version 2.43 could, with a crafted response from the configured DNS server, result in a violation of the DNS specification that causes the application to treat a non-answer section of the DNS response as a valid answer.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Gnu | Glibc | >= 2.34, <= 2.43 |
References
- https://sourceware.org/bugzilla/show_bug.cgi?id=34014Exploit, Issue Tracking, Patch
Timeline
- Published
- Last Modified
- Status
- Modified
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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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