Quick answers
- Is CVE-2026-88388 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-88388 being exploited in the wild.
- How severe is CVE-2026-88388?
- High severity, with a CVSS score of 7.5, published 24 September 2026.
- Which products and versions are affected?
- Espruino 2v29 (commit bffc6d0) and possibly earlier 64-bit builds.
- Is there a fix for CVE-2026-88388?
- A patch was published on 2026-09-24: Fix available in commit ecd7d43 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-88388 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-88388?
- Check whether you run Espruino 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
A type mismatch in jslPrintTokenLineMarker() passes a 4-byte int pointer to jsvGetLineAndCol() as a size_t pointer, which performs an 8-byte write and corrupts adjacent stack memory. The vulnerability is triggered via remote JavaScript input that reaches the error stack-trace code path on 64-bit builds. Stack memory corruption can lead to control flow hijacking or arbitrary code execution.
Affected products
- Espruino Espruino 2v29 (commit bffc6d0) and possibly earlier 64-bit builds
Timeline
- 2026-09-24: disclosed
- 2026-09-24: patched: Fix available in commit ecd7d43