Node.js HTTP/2 Re-entrant Heap UAF from nghttp2
CVE-2026-56848 Published on August 4, 2026
A flaw in Node.js HTTP/2 handling allows `nghttp2_session_mem_send()` to be called re-entrantly while `nghttp2_session_mem_recv()` is executing, resulting in a heap-use-after-free. This vulnerability affects Node.js **26.x**, **24.x**, and **22.x**.
Weakness Type
What is a Dangling pointer Vulnerability?
Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.
CVE-2026-56848 has been classified to as a Dangling pointer vulnerability or weakness.
Affected Versions
nodejs node:- Version 26.5.0, <= 26.5.0 is affected.
- Version 24.18.0, <= 24.18.0 is affected.
- Version 22.23.1, <= 22.23.1 is affected.