CVE-2026-56848
Description
A heap use-after-free vulnerability in the Node.js HTTP/2 component allows a remote attacker to crash the application, causing a denial of service. This is triggered by an unexpected re-entrant call to nghttp2_session_mem_send() while nghttp2_session_mem_recv() is still executing.
Statement
A remote attacker can exploit an Important heap use-after-free vulnerability in Node.js HTTP/2 to crash applications. The flaw, caused by re-entrant memory operations, leads to a denial of service for Red Hat environments with HTTP/2 enabled.
Mitigation
Restrict network access to Node.js HTTP/2 listeners to trusted clients only. If HTTP/2 is not required, disable it to remove the vulnerable handler from the attack surface.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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