CVE-2026-120439 json
QuickJS-NG before 0.16.0 Heap Buffer Overflow via TypedArray.prototype.sort
published 7d ago modified 3d ago also EUVD-2026-115199
- cvss
- 7.0
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 28%
- public exploits
- 0
- none known
Summary
QuickJS-NG before 0.16.0 contains an integer overflow in js_typed_array_sort() in quickjs.c that allows attackers to cause a heap buffer overflow on 32-bit hosts. Attackers who can run JavaScript can call TypedArray.prototype.sort with a comparator on a typed array near 2^30 elements, wrapping the allocation size and writing indices past the buffer to crash or potentially execute code.
Patch / fix
Is CVE-2026-120439 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 3d ago
Exploit prediction
0.34% chance of exploitation in the next 30 days, higher than 28% of all scored CVEs (FIRST EPSS, 2026-11-09).
Exploits and checks
- github.com https://github.com/quickjs-ng/quickjs/security/advisories/GHSA-9wv5-5cgr-grj6 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 8.3 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N |
| CNA | 3.1 | 7.0 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H |
| CNA | 4.0 | 8.3 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- quickjs-ng QuickJS-NG
Classification
- Weakness
-
- CWE-190 Integer Overflow or Wraparound
References
-
github.com
/quickjs-ng/quickjs/commit/e93cca611908e12b824ec85fbee6b31a5ee61568
patch
-
github.com
/quickjs-ng/quickjs/security/advisories/GHSA-9wv5-5cgr-grj6
vendor-advisory, exploit
-
github.com
/quickjs-ng/quickjs/releases/tag/v0.16.0
release-notes
-
github.com
/quickjs-ng/quickjs/blob/v0.15.1/quickjs.c#L60032
technical-description
-
vulncheck.com
/advisories/quickjs-ng-before-0.16.0-heap-buffer-overflow-via-typedarray-prototype-sort
third-party-advisory
Sources
- CVE List CVE-2026-120439
- NVD CVE-2026-120439
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.