What is CVE-2026-88388?
Espruino 2v29 (commit bffc6d0) contains a stack-based buffer overflow vulnerability in the JavaScript error stack-trace handling path on 64-bit builds. A remote attacker can supply JavaScript input that triggers an exception and reaches jslPrintTokenLineMarker(), which passes the address of a 4-byte int column variable to jsvGetLineAndCol() as a size_t pointer. jsvGetLineAndCol() performs an 8-byte write through the mismatched pointer, overwriting adjacent stack memory.
The record classifies CVE-2026-88388 under weakness class CWE-121. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on availability. The identifier was first published 11 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 7.5 — HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS (FIRST)
- 0.3% probability of exploitation in the next 30 days, higher than 22.3% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 4.6/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-09-24, last modified 2026-09-25
Is CVE-2026-88388 being exploited?
It currently carries a trending score of 34 in the Threadlinqs vulnerability feed.
Affected products and versions
No affected-product or package list has been recorded for CVE-2026-88388 in the tracked sources. The vendor advisory and the references below are the authoritative statement of what is affected.
How to fix CVE-2026-88388
No vendor patch reference has been recorded for CVE-2026-88388 in the tracked sources. Follow the references below for a fix, and treat any affected deployment as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-88388
No threat campaign in the Threadlinqs corpus currently references CVE-2026-88388, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.
Sources
Enriched from CVE.org, FIRST EPSS. Last verified by Threadlinqs on .