QuickJS-NG before 0.16.0 Memory Leak via Atomics.store
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 0.16.0
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 0.16.0.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 17/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Unclear
- Fix
- Fixed in 0.16.0
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: yes
- Technical impact: partial
Summary
QuickJS-NG, a lightweight JavaScript engine, is affected by this flaw in its Atomics.store implementation. An attacker who can run JavaScript code could repeatedly trigger the bug to consume heap memory until the program crashes or becomes unavailable.
Read the original description
QuickJS-NG before 0.16.0 contains a memory leak vulnerability in js_atomics_store() 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.
What to do
Upgrade to a fixed version: 0.16.0.
Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: none · Automatable: yes · Technical impact: partial
- Record last updated
Affected versions
- quickjs-ng QuickJS-NG
fixed in 0.16.0
Evidence 5
- Advisory
- Patch
- Repository
- Repository
- Link
Corrections
None so far.
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Questions about CVE-2026-120440
What does this mean?
When a BigInt64Array or BigUint64Array backed by a SharedArrayBuffer is detached during an Atomics.store() call, QuickJS-NG leaks memory that is never reclaimed. Repeated occurrences can exhaust memory and cause a denial of service.Source: github.com
Am I affected, and how do I check?
QuickJS-NG versions before 0.16.0 are affected. The bug needs a BigInt64Array or BigUint64Array backed by a SharedArrayBuffer that gets detached between the type check and the store inside Atomics.store(). To check a version, look at the QuickJS-NG release or package version in your build or dependency manifest.Source: github.com
What should I do about it?
Upgrade QuickJS-NG to 0.16.0 or later, which is the version range given as fixed. No vendor-specified workaround is listed in the checked facts.Source: github.com
Is it being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data