CVE catalog

CVE-2026-4438

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 result in an invalid DNS hostn

[CVE catalog]

Severity: Medium · CVSS 4.7CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N
Published: Mar 20, 2026, 7:59:06 PM UTC
Source: [NVD] · [CVE record]
EPSS: 0.33% · Oct 22, 2026

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	glibc	sid	`2.43-7`	fixed
Debian	glibc	forky	`2.43-7`	fixed
Debian	glibc	trixie	`2.41-12+deb13u4`	fixed
Debian	glibc	bookworm	`2.36-9+deb12u14`	fixed
Debian	glibc	bookworm-security	`2.36-9+deb12u7`	vulnerable
Cpe	glibc	Not reported	`2.36-9+deb12u14`	fixed
Ubuntu	glibc	noble	`2.39-0ubuntu8.8`	fixed
Ubuntu	glibc-doc	noble	`2.39-0ubuntu8.8`	fixed
Ubuntu	glibc-source	noble	`2.39-0ubuntu8.8`	fixed
Ubuntu	libc-bin	noble	`2.39-0ubuntu8.8`	fixed
Ubuntu	libc-dev-bin	noble	`2.39-0ubuntu8.8`	fixed
Ubuntu	libc-devtools	noble	`2.39-0ubuntu8.8`	fixed
Ubuntu	libc6	noble	`2.39-0ubuntu8.8`	fixed
Ubuntu	libc6-amd64	noble	`2.39-0ubuntu8.8`	fixed
Ubuntu	libc6-dev	noble	`2.39-0ubuntu8.8`	fixed
Ubuntu	libc6-dev-amd64	noble	`2.39-0ubuntu8.8`	fixed
Ubuntu	libc6-dev-i386	noble	`2.39-0ubuntu8.8`	fixed
Ubuntu	libc6-dev-s390	noble	`2.39-0ubuntu8.8`	fixed
Ubuntu	libc6-dev-x32	noble	`2.39-0ubuntu8.8`	fixed
Ubuntu	libc6-i386	noble	`2.39-0ubuntu8.8`	fixed
Ubuntu	libc6-s390	noble	`2.39-0ubuntu8.8`	fixed
Ubuntu	libc6-x32	noble	`2.39-0ubuntu8.8`	fixed
Ubuntu	locales	noble	`2.39-0ubuntu8.8`	fixed
Ubuntu	locales-all	noble	`2.39-0ubuntu8.8`	fixed
Ubuntu	nscd	noble	`2.39-0ubuntu8.8`	fixed
Ubuntu	eglibc	pro	`2.17-93ubuntu4`	vulnerable
Ubuntu	eglibc	pro	`2.18-0ubuntu1`	vulnerable
Ubuntu	eglibc	pro	`2.18-0ubuntu2`	vulnerable
Ubuntu	eglibc	pro	`2.18-0ubuntu4`	vulnerable
Ubuntu	eglibc	pro	`2.18-0ubuntu5`	vulnerable
Ubuntu	eglibc	pro	`2.18-0ubuntu6`	vulnerable
Ubuntu	eglibc	pro	`2.18-0ubuntu7`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu2`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu3`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu4`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu5`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu6`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu6.1`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu6.3`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu6.4`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu6.5`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu6.6`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu6.7`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu6.8`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu6.9`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu6.10`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu6.11`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu6.13`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu6.14`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu6.15`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu6.15+esm1`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu6.15+esm2`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu6.15+esm3`	vulnerable
Ubuntu	eglibc	pro	`2.19-0ubuntu6.15+esm4`	vulnerable
Ubuntu	glibc	24.04	`2.38-1ubuntu6`	vulnerable
Ubuntu	glibc	24.04	`2.38-3ubuntu1`	vulnerable
Ubuntu	glibc	24.04	`2.39-0ubuntu1`	vulnerable
Ubuntu	glibc	24.04	`2.39-0ubuntu2`	vulnerable
Ubuntu	glibc	24.04	`2.39-0ubuntu6`	vulnerable
Ubuntu	glibc	24.04	`2.39-0ubuntu8`	vulnerable
Ubuntu	glibc	24.04	`2.39-0ubuntu8.1`	vulnerable
Ubuntu	glibc	24.04	`2.39-0ubuntu8.2`	vulnerable
Ubuntu	glibc	24.04	`2.39-0ubuntu8.3`	vulnerable
Ubuntu	glibc	24.04	`2.39-0ubuntu8.4`	vulnerable
Ubuntu	glibc	24.04	`2.39-0ubuntu8.5`	vulnerable
Ubuntu	glibc	24.04	`2.39-0ubuntu8.6`	vulnerable
Ubuntu	glibc	24.04	`2.39-0ubuntu8.7`	vulnerable
Ubuntu	glibc	24.04	`2.39-0ubuntu8.8`	fixed
Ubuntu	glibc	25.10	`2.41-6ubuntu1`	vulnerable
Ubuntu	glibc	25.10	`2.41-6ubuntu2`	vulnerable
Ubuntu	glibc	25.10	`2.41-9ubuntu1`	vulnerable
Ubuntu	glibc	25.10	`2.42-0ubuntu1`	vulnerable
Ubuntu	glibc	25.10	`2.42-0ubuntu3`	vulnerable
Ubuntu	glibc	25.10	`2.42-0ubuntu3.1`	vulnerable

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	glibc	source	sid	`2.42-14`	not yet assigned	Not reported	[1131887]
Debian	glibc	source	forky	`2.42-14`	not yet assigned	Not reported	[1131887]
Debian	glibc	source	trixie	`2.41-12+deb13u3`	not yet assigned	Not reported	[1131887]
Debian	glibc	source	bookworm	`2.36-9+deb12u14`	not yet assigned	Not reported	[1131887]
Cpe	glibc	cpe	Not reported	`2.36-9+deb12u14`	Not reported	Not reported	Not reported
Ubuntu	glibc	deb	noble	`2.39-0ubuntu8.8`	Not reported	Not reported	Not reported
Ubuntu	glibc-doc	deb	noble	`2.39-0ubuntu8.8`	Not reported	Not reported	Not reported
Ubuntu	glibc-source	deb	noble	`2.39-0ubuntu8.8`	Not reported	Not reported	Not reported
Ubuntu	libc-bin	deb	noble	`2.39-0ubuntu8.8`	Not reported	Not reported	Not reported
Ubuntu	libc-dev-bin	deb	noble	`2.39-0ubuntu8.8`	Not reported	Not reported	Not reported
Ubuntu	libc-devtools	deb	noble	`2.39-0ubuntu8.8`	Not reported	Not reported	Not reported
Ubuntu	libc6	deb	noble	`2.39-0ubuntu8.8`	Not reported	Not reported	Not reported
Ubuntu	libc6-amd64	deb	noble	`2.39-0ubuntu8.8`	Not reported	Not reported	Not reported
Ubuntu	libc6-dev	deb	noble	`2.39-0ubuntu8.8`	Not reported	Not reported	Not reported
Ubuntu	libc6-dev-amd64	deb	noble	`2.39-0ubuntu8.8`	Not reported	Not reported	Not reported
Ubuntu	libc6-dev-i386	deb	noble	`2.39-0ubuntu8.8`	Not reported	Not reported	Not reported
Ubuntu	libc6-dev-s390	deb	noble	`2.39-0ubuntu8.8`	Not reported	Not reported	Not reported
Ubuntu	libc6-dev-x32	deb	noble	`2.39-0ubuntu8.8`	Not reported	Not reported	Not reported
Ubuntu	libc6-i386	deb	noble	`2.39-0ubuntu8.8`	Not reported	Not reported	Not reported
Ubuntu	libc6-s390	deb	noble	`2.39-0ubuntu8.8`	Not reported	Not reported	Not reported
Ubuntu	libc6-x32	deb	noble	`2.39-0ubuntu8.8`	Not reported	Not reported	Not reported
Ubuntu	locales	deb	noble	`2.39-0ubuntu8.8`	Not reported	Not reported	Not reported
Ubuntu	locales-all	deb	noble	`2.39-0ubuntu8.8`	Not reported	Not reported	Not reported
Ubuntu	nscd	deb	noble	`2.39-0ubuntu8.8`	Not reported	Not reported	Not reported
Ubuntu	glibc	deb	24.04	`2.39-0ubuntu8.8`	Not reported	UBUNTU-CVE-2026-4438	Not reported

[Debian bug #1131887]

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[glibc-doc]Affected
Source package: [glibc]
Details (4)
- 2.36-9+deb12u14 · all · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u14 · all · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · all · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · all · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
[glibc-source]Affected
Source package: [glibc]
Details (4)
- 2.36-9+deb12u14 · all · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u14 · all · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · all · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · all · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
[libc6]Affected
Source package: [glibc]
Details (4)
- 2.36-9+deb12u14 · amd64 · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u14 · arm64 · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · amd64 · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · arm64 · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
[libc6-dbg]Affected
Source package: [glibc]
Details (4)
- 2.36-9+deb12u14 · amd64 · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u14 · arm64 · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · amd64 · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · arm64 · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
[libc6-dev]Affected
Source package: [glibc]
Details (4)
- 2.36-9+deb12u14 · amd64 · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u14 · arm64 · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · amd64 · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · arm64 · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
[libc6-dev-i386]Affected
Source package: [glibc]
Details (2)
- 2.36-9+deb12u14 · amd64 · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · amd64 · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
[libc6-dev-x32]Affected
Source package: [glibc]
Details (2)
- 2.36-9+deb12u14 · amd64 · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · amd64 · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
[libc6-i386]Affected
Source package: [glibc]
Details (2)
- 2.36-9+deb12u14 · amd64 · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · amd64 · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
[libc6-x32]Affected
Source package: [glibc]
Details (2)
- 2.36-9+deb12u14 · amd64 · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · amd64 · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
[libc-bin]Affected
Source package: [glibc]
Details (4)
- 2.36-9+deb12u14 · amd64 · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u14 · arm64 · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · amd64 · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · arm64 · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
[libc-dev-bin]Affected
Source package: [glibc]
Details (4)
- 2.36-9+deb12u14 · amd64 · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u14 · arm64 · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · amd64 · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · arm64 · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
[libc-devtools]Affected
Source package: [glibc]
Details (4)
- 2.36-9+deb12u14 · amd64 · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u14 · arm64 · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · amd64 · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · arm64 · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
[libc-l10n]Affected
Source package: [glibc]
Details (4)
- 2.36-9+deb12u14 · all · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u14 · all · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · all · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · all · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
[locales]Affected
Source package: [glibc]
Details (4)
- 2.36-9+deb12u14 · all · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u14 · all · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · all · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · all · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
[locales-all]Affected
Source package: [glibc]
Details (4)
- 2.36-9+deb12u14 · amd64 · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u14 · arm64 · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · amd64 · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · arm64 · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
[nscd]Affected
Source package: [glibc]
Details (4)
- 2.36-9+deb12u14 · amd64 · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u14 · arm64 · bookworm
  Fixed · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · amd64 · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12
- 2.36-9+deb12u7 · arm64 · bookworm-security
  Affected · Fixed: 2.36-9+deb12u14
  nvd · glibc · debian · bookworm; nvd · glibc · debian · 12

[Debian 13 (Trixie)]

[glibc-doc]Fixed
Source package: [glibc]
Details (2)
- 2.41-12+deb13u3 · all · trixie
  Fixed · Fixed: 2.41-12+deb13u3
  nvd · glibc · debian · 13
- 2.41-12+deb13u3 · all · trixie
  Fixed · Fixed: 2.41-12+deb13u3
  nvd · glibc · debian · 13
[glibc-source]Fixed
Source package: [glibc]
Details (2)
- 2.41-12+deb13u3 · all · trixie
  Fixed · Fixed: 2.41-12+deb13u3
  nvd · glibc · debian · 13
- 2.41-12+deb13u3 · all · trixie
  Fixed · Fixed: 2.41-12+deb13u3
  nvd · glibc · debian · 13
[libc6]Fixed
Source package: [glibc]
Details (2)
- 2.41-12+deb13u3 · amd64 · trixie
  Fixed · Fixed: 2.41-12+deb13u3
  nvd · glibc · debian · 13
- 2.41-12+deb13u3 · arm64 · trixie
  Fixed · Fixed: 2.41-12+deb13u3
  nvd · glibc · debian · 13
[libc6-dbg]Fixed
Source package: [glibc]
Details (2)
- 2.41-12+deb13u3 · amd64 · trixie
  Fixed · Fixed: 2.41-12+deb13u3
  nvd · glibc · debian · 13
- 2.41-12+deb13u3 · arm64 · trixie
  Fixed · Fixed: 2.41-12+deb13u3
  nvd · glibc · debian · 13

Next results

Observed: Oct 23, 2026, 10:39:44 PM UTC

References

[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX] · [Ubuntu Security Notices (USN)]