Quick answers
- Is CVE-2026-88362 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-88362 being exploited in the wild.
- How severe is CVE-2026-88362?
- High severity, with a CVSS score of 7.5, published 24 September 2026.
- Which products and versions are affected?
- Artifex Mujs commit e892c9fdb and affected prior versions.
- Is there a fix for CVE-2026-88362?
- A patch was published on 2026-08-19: Fix committed in 8a32c397b28fe45747ac4e9e4f3dca049825eda7 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-88362 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-88362?
- Check whether you run Artifex Mujs at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The jsR_isindex() function in jsrun.c performs an implicit cast of a double-precision floating-point value to a 32-bit signed integer without range validation. When the double value exceeds INT_MAX or is negative, the conversion is undefined behavior in C. An attacker provides malicious JavaScript code (e.g., array access with index 2222222222222222) to trigger out-of-range conversion. The fix adds explicit range checking before the cast.
Affected products
- Artifex MuJS commit e892c9fdb and affected prior versions
Timeline
- 2026-08-07: disclosed
- 2026-08-19: patched: Fix committed in 8a32c397b28fe45747ac4e9e4f3dca049825eda7
- 2026-09-24: advisory