CVE-2025-62408 c-ares has a Use After Free vulnerability when connection is cleaned up after error
A use-after-free flaw in c-ares allows attackers to cause a denial of service by triggering specific error conditions during query termination.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-62408?
CVE-2025-62408 is a medium-severity use after free vulnerability in c-ares, published on 8 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-416
Which versions are affected by CVE-2025-62408?
It affects 1 product.
Linux distribution packages (4)
c-ares Red Hat:hummingbird:1 | All versions | 0:1.34.6-3.1.hum1 |
c-ares-devel Red Hat:hummingbird:1 | All versions | 0:1.34.6-3.1.hum1 |
c-ares openSUSE:Tumbleweed | All versions | 1.34.6-1.1 |
istioctl openSUSE:Tumbleweed | All versions | 1.28.2-1.1 |
Products include C-Ares C-Ares.
How do I fix CVE-2025-62408?
Upgrade to a fixed version.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2025-62408 being exploited?
There is no known exploitation of CVE-2025-62408 in the wild and no public exploit code.
Other vulnerabilities in c-ares
Sources
Also known as ALPINE-CVE-2025-62408, AZL-71854, BELL-CVE-2025-62408, CLEANSTART-2026-CV14251, CLEANSTART-2026-ES22534, CLEANSTART-2026-PA08488 and 15 more.