CVE-2026-8674

CVE Details

Release Date:	2026-09-17
Impact:	Moderate	What is this?

Description

Initializing the DNS stub resolver from an /etc/resolv.conf file, or a LOCALDOMAIN environment variable, whose search list contains a domain of roughly 200 characters or more in the GNU C Library version 2.26 to 2.44 results in an assertion failure which aborts the process. The resolver truncates the search list when copying it into the fixed-size _res.defdname buffer, then asserts that the copy is consistent with the full configuration. The consistency check compared against the wrong size and did not handle a first entry that does not fit, so a correctly truncated list failed the assertion. Any process that resolves names through the library is affected, including long-running processes that reload /etc/resolv.conf on the next query after it changes. Search domains are commonly written to /etc/resolv.conf from data received over DHCP or from a VPN server, so an attacker on the local network may be able to trigger this without privileges on the target system, subject to validation by the network configuration software.

See more information about CVE-2026-8674 from MITRE CVE dictionary and NIST NVD

NOTE: The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 metrics

Base Score:	5.3
Vector String:	CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Version:	3.1
Attack Vector:	Adjacent_Network
Attack Complexity:	High
Privileges Required:	None
User Interaction:	None
Scope:	Unchanged
Confidentiality Impact:	None
Integrity Impact:	None
Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 10 (glibc)	ELSA-2026-84753	2026-11-02