Description
MuJS 1.3.6 before 1.3.9 contains a heap out-of-bounds read and write vulnerability in Array.prototype.sort that allows attackers to corrupt memory by inflating a simple array's length. Attackers can supply JavaScript that enlarges a dense array's length and calls sort, causing Ap_sort_cmp and Ap_sort_swap to access slots past the buffer and crash the process.
Metrics
CVSS 3.1 6.1/10
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:HWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| Artifex Software | MuJS | >= 1.3.6, < 1.3.9 |
References
- https://codeberg.org/ccxvii/mujs
- https://codeberg.org/ccxvii/mujs/commit/32064e10caa45e68fc87331ca53d042049cc9396
- https://codeberg.org/ccxvii/mujs/src/commit/307f18c4216420f2f56e22d8e7040baa39a6304a/jsarray.c#L245
- https://hackmd.io/@haind-pwn/mujs-array-length-flat-oob
- https://mujs.com/downloads/
- https://www.vulncheck.com/advisories/mujs-1.3.6-before-1.3.9-heap-out-of-bounds-read-write-via-array-prototype-sort
Timeline
- Published
- Oct 14, 2026
- Last modified
- Oct 15, 2026
- NVD status
- Deferred