CVE-2026-4437
CVE-2026-4437 · gethostbyaddr and gethostbyaddr_r may incorrectly handle DNS response
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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.
CVSS 7.5 · High · EPSS 0.3% · Fix available
- Published
- Updated
Stack: system
Affected products and versions
glibc
- Versions
- ≥ 2.34, ≤ 2.43: Affected (custom)
No fix published
glibc Debian:12
- Versions
- 2.36-9
- 2.36-9+deb12u1
- 2.36-9+deb12u10
- 2.36-9+deb12u11
- 2.36-9+deb12u12
- 2.36-9+deb12u13
- 2.36-9+deb12u2
- 2.36-9+deb12u3
- 2.36-9+deb12u4
- 2.36-9+deb12u5
- 2.36-9+deb12u6
- 2.36-9+deb12u7
- 2.36-9+deb12u8
- 2.36-9+deb12u9
- Affected ranges
- ECOSYSTEM: < 2.36-9+deb12u14
Update to 2.36-9+deb12u14
glibc Debian:13
- Versions
- 2.41-12
- 2.41-12+deb13u1
- 2.41-12+deb13u2
- Affected ranges
- ECOSYSTEM: < 2.41-12+deb13u3
Update to 2.41-12+deb13u3
glibc Debian:14
- Versions
- 2.41-12
- 2.41-13~hurd.0
- 2.41-13~hurd.1
- 2.42-1
- 2.42-10
- 2.42-11
- 2.42-12
- 2.42-12~hurd.1
- 2.42-13
- 2.42-14~hurd.1
- 2.42-2
- 2.42-3
- 2.42-4
- 2.42-5
- 2.42-6
- 2.42-7
- 2.42-8
- 2.42-8~hurd.1
- 2.42-8~hurd.2
- 2.42-9
- Affected ranges
- ECOSYSTEM: < 2.42-14
Update to 2.42-14
eglibc Ubuntu:Pro:14.04:LTS
- Versions
- 2.17-93ubuntu4
- 2.18-0ubuntu1
- 2.18-0ubuntu2
- 2.18-0ubuntu4
- 2.18-0ubuntu5
- 2.18-0ubuntu6
- 2.18-0ubuntu7
- 2.19-0ubuntu2
- 2.19-0ubuntu3
- 2.19-0ubuntu4
- 2.19-0ubuntu5
- 2.19-0ubuntu6
- 2.19-0ubuntu6.1
- 2.19-0ubuntu6.3
- 2.19-0ubuntu6.4
- 2.19-0ubuntu6.5
- 2.19-0ubuntu6.6
- 2.19-0ubuntu6.7
- 2.19-0ubuntu6.8
- 2.19-0ubuntu6.9
- 2.19-0ubuntu6.10
- 2.19-0ubuntu6.11
- 2.19-0ubuntu6.13
- 2.19-0ubuntu6.14
- 2.19-0ubuntu6.15
- 2.19-0ubuntu6.15+esm1
- 2.19-0ubuntu6.15+esm2
- 2.19-0ubuntu6.15+esm3
- 2.19-0ubuntu6.15+esm4
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
glibc Ubuntu:24.04:LTS
- Versions
- 2.38-1ubuntu6
- 2.38-3ubuntu1
- 2.39-0ubuntu1
- 2.39-0ubuntu2
- 2.39-0ubuntu6
- 2.39-0ubuntu8
- 2.39-0ubuntu8.1
- 2.39-0ubuntu8.2
- 2.39-0ubuntu8.3
- 2.39-0ubuntu8.4
- 2.39-0ubuntu8.5
- 2.39-0ubuntu8.6
- 2.39-0ubuntu8.7
- Affected ranges
- ECOSYSTEM: < 2.39-0ubuntu8.8
Update to 2.39-0ubuntu8.8
glibc Ubuntu:25.10
- Versions
- 2.41-6ubuntu1
- 2.41-6ubuntu2
- 2.41-9ubuntu1
- 2.42-0ubuntu1
- 2.42-0ubuntu3
- 2.42-0ubuntu3.1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published