CVE-2026-18924 HTTP/2 server push UAF
A use-after-free in libcurl's HTTP/2 server push handling when sharing connections allows attackers to potentially execute code or cause denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-18924?
CVE-2026-18924 is a critical use after free vulnerability in Haxx Curl, published on 6 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A flaw in libcurl's handling of HTTP/2 Server Push streams, when the parent handle is set to share connections with other handles, can lead to use-after-free in the cleanup process.
Weakness: CWE-416
Which versions are affected by CVE-2026-18924?
It affects 1 product.
Products include Haxx Curl.
How do I fix CVE-2026-18924?
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-2026-18924 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-18924 exists.
Other vulnerabilities in Haxx Curl
Sources
Also known as ALPINE-CVE-2026-18924, AZL-99764, AZL-99780, AZL-99801, AZL-99834, AZL-99858 and 17 more.