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Fencer Vulns
medium 6.2

CVE-2026-88389 json

Espruino 2v29 (commit bffc6d0) contains a NULL pointer dereference vulnerability in jslGetRawString() in src/jslex.c.

published 2026-09-25 45 d ago modified 2026-09-30 39 d ago also EUVD-2026-87108

cvss
6.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 5%
public exploits
0
none known

Summary

Espruino 2v29 (commit bffc6d0) contains a NULL pointer dereference vulnerability in jslGetRawString() in src/jslex.c. Crafted raw/binary string input can cause the lexer to pass a NULL iterator target to jsvLockAgain(). In RELEASE/NO_ASSERT builds, the missing assertion guard allows a write through the NULL pointer, resulting in memory corruption and application termination or denial of service.

Patch / fix

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
41 d ago

Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/espruino/Espruino/issues/2745 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 6.2 CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 6.2 CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.