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Security Advisories

CVE-2026-4437

NVD

https://nvd.nist.gov/vuln/detail/CVE-2026-4437

Severity

7.5

High

CVSS V3

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Summary

gethostbyaddr and gethostbyaddr_r may incorrectly handle DNS response

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.

References

  • https://nvd.nist.gov/vuln/detail/CVE-2026-4437
  • https://github.com/advisories/GHSA-m5wq-r4r4-4qrh
  • https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/4xxx/CVE-2026-4437.json
  • https://sourceware.org/bugzilla/show_bug.cgi?id=34014
  • https://cert-portal.siemens.com/productcert/html/ssa-082556.html

Affected packages

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