Memory Leak Vulnerability in QuickJS-NG Affects Heap Memory Management
CVE-2026-120440

6.9MEDIUM

Key Information:

Vendor

Quickjs-ng

Status
Quickjs-ng
Vendor
CVE Published:
2 November 2026

What is CVE-2026-120440?

QuickJS-NG prior to version 0.16.0 has a memory leak vulnerability in the js_atomics_store() function within quickjs.c. This issue arises when the function fails to release the converted value after returning a RangeError. Malicious users can exploit this flaw by repeatedly invoking Atomics.store with a valueOf that either detaches or reduces the buffer, which can ultimately exhaust the system's heap memory and trigger a denial of service.

Affected Version(s)

QuickJS-NG 0 < 0.16.0

References

https://github.com/quickjs-ng/quickjs/security/advisories...
vendor-advisory
https://github.com/quickjs-ng/quickjs/commit/62951e1bc687...
patch
https://github.com/quickjs-ng/quickjs/releases/tag/v0.16.0
release-notes

CVSS V4

Score:
6.9
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Tristan Madani (Talence Security)
Saúl Ibarra Corretgé
.