CVE-2025-62408

Publication date 8 December 2025

Last updated 11 December 2025

Ubuntu priority

Cvss 3 Severity Score

Description

c-ares is an asynchronous resolver library. Versions 1.32.3 through 1.34.5 terminate a query after maximum attempts when using read_answer() and process_answer(), which can cause a Denial of Service. This issue is fixed in version 1.34.6.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
c-ares	25.10 questing	Fixed 1.34.5-1ubuntu0.1
	25.04 plucky	Fixed 1.34.4-2.1ubuntu0.2
	24.04 LTS noble	Not affected
	22.04 LTS jammy	Not affected
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected

Notes

mdeslaur

issue introduced in 1.32.3

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
c-ares	Upstream: 714bf56 Upstream: abf0049

Severity score breakdown

Parameter	Value
Base score	5.9 · Medium
Attack vector	Network
Attack complexity	High
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

USN-7925-1
c-ares vulnerability
11 December 2025