CVE-2026-88389

MEDIUMPre-NVD 6.26.2—
EchelonGraph scoreHIGH confidence

Score 6.2 from GitHub Security Advisory published 2026-09-25. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 6.2; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 4 sources updated this weekElevated
6.2EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.1%CVSS: 6.2Exploit: Elevated riskExposed services: Not assessed

An upstream fix is merged but not yet released — mitigate (WAF / firewall / segmentation) until the release ships, then apply it.

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.

CVSS v3
6.2
EG Score
6.2MEDIUMhigh confidence
EG Risk
44
EG Risk 44/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity62% × 45%
Exploitation40% × 40%
Automatability0% × 15%
CISA SSVC: Track at low or medium mission impact; Track* at high (mission-essential systems).
Action: An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines until it ships, then apply the release.
EPSS PROB
0.1%
EPSS %ILE
1st
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* at high (mission-essential systems).

An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines until it ships, then apply the release.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 25, 2026

Last Modified

September 30, 2026

Advisory Details (2)

Auto-updated Sep 29, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit.
github_commit

commit 0db0663ac520 (espruino/Espruino)

Fix landed in espruino/Espruino commit 0db0663ac520 — awaiting tagged release

https://github.com/espruino/Espruino/commit/0db0663ac5201a6fea68094b45da673edec45187
generic

[Bug]Malformed raw-string makes jslGetRawString call jsvLockAgain on a NULL iterator target: NULL-pointer dereference masked by assert; real NULL deref under RELEASE/NO_ASSERT (CWE-476) · Issue #2745 · espruino/Espruino · GitHub

https://github.com/espruino/Espruino/issues/2745

Vendor Advisories for CVE-2026-88389(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 19× in last 7d / 23× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-03 20:02 UTCEG score recompute
  2. 2026-10-03 20:02 UTCGHSA enrichment
  3. 2026-10-02 19:18 UTCEG score recompute
  4. 2026-10-02 19:18 UTCGHSA enrichment
  5. 2026-10-01 19:51 UTCEPSS rescore
  6. 2026-10-01 18:34 UTCGHSA enrichment
  7. 2026-09-30 17:48 UTCEG score recompute
  8. 2026-09-30 17:48 UTCGHSA enrichment
  9. 2026-09-30 15:04 UTCEPSS rescore
  10. 2026-09-30 05:16 UTCEG score recompute
  11. 2026-09-30 05:16 UTCGHSA enrichment
  12. 2026-09-29 04:31 UTCEG score recompute
  13. 2026-09-29 04:31 UTCGHSA enrichment
  14. 2026-09-29 03:40 UTCEG score recompute▲ 6.20
  15. 2026-09-29 03:40 UTCGHSA enrichment
  16. 2026-09-29 03:40 UTCMITRE cvelistV5CVSS v3 → 6.2 · severity → MEDIUM
  17. 2026-09-28 13:52 UTCEPSS rescore
  18. 2026-09-28 09:13 UTCEG score recompute
  19. 2026-09-28 09:13 UTCGHSA enrichment
  20. 2026-09-26 15:59 UTCEPSS rescore
  21. 2026-09-25 15:23 UTCNVD update
  22. 2026-09-25 14:24 UTCEG score recompute
  23. 2026-09-25 14:24 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-88389?
CVE-2026-88389 is a medium vulnerability published on September 25, 2026. 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…
When was CVE-2026-88389 disclosed?
CVE-2026-88389 was first published on September 25, 2026, with the most recent update on September 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-88389 actively exploited?
CVE-2026-88389 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.1% probability of exploitation in the next 30 days (1st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-88389?
CVE-2026-88389 has a CVSS v3.1 base score of 6.2 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-88389?
An upstream fix for CVE-2026-88389 has been merged but is not yet in a tagged release. Until it ships, restrict network exposure of the affected system or apply the vendor's mitigation, then update to the release that contains the fix. The vendor advisories EchelonGraph has for CVE-2026-88389 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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