Use After Free in Node.js Node

CVE-2026-56848

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**.

Vulnerability class: Use-After-Free

EPSS: 0.005 (41.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-56848?
CVE-2026-56848 is a high-severity vulnerability in Node.js Node, classified under Use After Free. CVSS score: 7.5/10. Published 2026-08-04.
How severe is CVE-2026-56848?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2026-56848 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.