QuickJS-NG before 0.16.0 contains a memory leak vulnerability in js_atomics_store() in quickjs.c that fails to free
Affects quickjs-ngSource GCVE Database
Not known to be exploited · CVSS 6.9 Medium · fixed in 0.16.0 : update quickjs-ng when convenient.
Data as of 5 Nov 2026, 12:37 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 6.9 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 5.3 |
| CNA | CVSS 4.0 | 6.9 |
- Patch
- Available – fixed in 0.16.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 2 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10quickjs-ngpkg:deb/ubuntu/quickjs-ng?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available in QuickJS-NG version 0.16.0 and later. Users should upgrade to version 0.16.0 or newer to remediate this vulnerability.
Description
QuickJS-NG versions before 0.16.0 have a memory leak vulnerability in the js_atomics_store() function. This flaw occurs when the function fails to free a converted value upon returning a RangeError. An attacker running JavaScript can exploit this by repeatedly calling Atomics.store with a crafted valueOf that detaches or shrinks the buffer, leading to heap memory exhaustion and denial of service.
References
- ubuntu.com/security/CVE-2026-120440 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-120440 (opens in a new tab)
- github.com/quickjs-ng/quickjs/blob/v0.15.1/quickjs.c (opens in a new tab)
- github.com/quickjs-ng/quickjs/commit/62951e1bc68711d37aad986ff84ef0fe17038a7e (opens in a new tab)
- github.com/quickjs-ng/quickjs/releases/tag/v0.16.0 (opens in a new tab)
- github.com/quickjs-ng/quickjs/security/advisories/GHSA-wm7w-r6qf-3c9w (opens in a new tab)
- vulncheck.com/advisories/quickjs-ng-before-0.16.0-memory-leak-via-atomics-store (opens in a new tab)