What is 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**.
The record classifies CVE-2026-56848 under weakness class CWE-416. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 67 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 7.5 — HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS (FIRST)
- 0.4% probability of exploitation in the next 30 days, higher than 40.2% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 7.4/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-08-04
Is CVE-2026-56848 being exploited?
Weaponised exploit code for CVE-2026-56848 is publicly available. 1 public proof-of-concept repository is tracked for this identifier. It currently carries a trending score of 36 in the Threadlinqs vulnerability feed.
- open-flaw/CVE-2026-56848 (github)
Affected products and versions
- nodejs: node
How to fix CVE-2026-56848
No vendor patch reference has been recorded for CVE-2026-56848 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-56848
1 tracked threat in the Threadlinqs corpus references CVE-2026-56848, either in the campaign’s CVE list or as an indicator on the campaign record.
Sources
Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories, public proof-of-concept repositories. Last verified by Threadlinqs on .