CVE-2026-4437CWE-125

gethostbyaddr and gethostbyaddr_r may incorrectly handle DNS response

High · published March 20, 2026

CVSS v3.1
7.5
EPSS
0%
Percentile
26.0
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00338 · 26.0th percentile
Weakness
CWE-125 · Out-of-bounds Read
Published
2026-03-20T19:59Z
EPSS history
Timeline
  • 20 MAR 19:59Z
    gethostbyaddr and gethostbyaddr_r may incorrectly handle DNS response
    cvelistv5