CVE-2026-88390

An out-of-bounds write vulnerability in jslGetTokenValueAsString() in Espruino 2v29 (commit bffc6d0) allows crafted JavaScript input containing an overlong token to trigger a one-byte write beyond the JsLex.token buffer in RELEASE/NO_ASSERT builds. The out-of-bounds write corrupts the adjacent tokenValue pointer, resulting in memory corruption and potentially causing application crashes or denial of service.

  • Published Sep 24, 2026
  • CVSS 7.7 high
  • 0.2% chance of exploitation in the next 30 days (EPSS)
  • A fix is available

CVE-2026-88390 at the National Vulnerability Database