gethostbyaddr and gethostbyaddr_r may incorrectly handle DNS response
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.
CVE-2026-4437
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-4437
glibc
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "The GNU C Library",
"product": "glibc",
"versions": [
{
"status": "affected",
"version": "2.34",
"versionType": "custom",
"lessThanOrEqual": "2.43"
}
],
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-4437
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #28356 · Revision 1
- Added to Heist Feed
- Publisher date