CVE-2026-4438
gethostbyaddr and gethostbyaddr_r return invalid DNS hostnames
MEDIUM 5.4
At a glance
- Source
- NVD
- EPSS
- EPSS 0.33 % · percentile 26 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- glibc
- NVD status
- Modified
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 result in an invalid DNS hostname being returned to the caller in violation of the DNS specification.
Weaknesses (CWE)
- CWE-20 — Improper Input Validation
- CWE-88 — Improper Neutralization of Argument Delimiters in a Command
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 5.4 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N | CISA-ADP |
| CVSS 3.1 | MEDIUM 5.4 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N | NVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary) |
European references
- ENISA EUVD · EUVD-2026-13798
- GCVE · GCVE-0-2026-4438
CERT-FR advisories
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0376 — Multiples vulnérabilités dans les produits Microsoft · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:gnu:glibc:*:*:*:*:*:*:*:*≥ 2.34 ≤ 2.43
Affected products
| Product | Versions |
|---|---|
| The GNU C Library · glibc | affected 2.34 ≤ 2.43 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |