Is there a public exploit for CVE-2026-120440?

No public exploit for CVE-2026-120440 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-120440?

CVE-2026-120440 scores CVSS 6.9 (v4.0), rated medium.

What does CVE-2026-120440 affect?

CVE-2026-120440 affects quickjs-ng QuickJS-NG.

6.9 Medium

QuickJS-NG before 0.16.0 contains a memory leak vulnerability in jsatomicsstore() in quickjs.c that fails to free the converted value when…

CVE-2026-120440

QuickJS-NG before 0.16.0 contains a memory leak vulnerability in jsatomicsstore() in quickjs.c that fails to free the converted value when returning a RangeError. Attackers running JavaScript can repeatedly call Atomics.store with a valueOf that detaches or shrinks the buffer to exhaust heap memory and cause denial of service.

Assessment

CVSS: 6.9 (v4.0)
Severity: Medium
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 2 November 2026
Last updated: 2 November 2026
Affected: quickjs-ng · QuickJS-NG
Assigner: VulnCheck

CVSS vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

At the source

EUVD (ENISA)

References

Community proofs of concept

No community proof of concept yet. If you have one for a published vulnerability and the right to share it, add it below — it will appear here once reviewed.

Submit a proof of concept

Only for publicly disclosed vulnerabilities, and only material from testing you were authorised to perform. This platform does not buy, sell, or broker exploits — see earning from vulnerability research for legitimate bounty programs. Submissions are reviewed before they appear. Text only; do not include live credentials, personal data, or anything targeting systems you are not permitted to test.

Title *

Proof of concept *

Write-up (optional)

Affected versions (optional)

Name or handle (optional)

References (optional, one URL per line)

Licence for your contribution *

Private contact (optional, never shown)

Before you submit * This vulnerability is already publicly disclosed (it has a published CVE). This material comes only from testing I was authorised to perform. I have the legal right to publish this content and am not breaching any agreement by doing so. It contains no live credentials, personal data, or anything targeting systems I am not authorised to test. I understand it will be reviewed before it appears publicly and may be rejected. I agree to the submission terms.

What is 2 + 1? *

Query this programmatically

Agents can read this through the MCP endpoint, or over HTTP:

curl https://cve.zerocrew.in/api/cve/CVE-2026-120440