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 cou…

Code

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Timeline

Detection, updates, and resolution for this record.

1. Mar 20, 2026 · NIST NVD

   Detected

   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.

2. Jul 14, 2026 · NIST NVD

   Updated

   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.

Affected

• cpe gnu/glibcversion unspecified

Sources

• CVE.orgVulnerability recordCVE-2026-4437

  Official CVE identifier

  cve.org
• NIST NVDVulnerability recordCVE-2026-4437

  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 c

  nvd.nist.gov

References

• Reference · cert-portal.siemens.com
• Exploit · sourceware.org