CVE-2026-86056

MEDIUMPre-NVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2% (4th percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Elevated
5.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 5.5Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

Notepad++ is a free and open-source source code editor. Prior to 8.9.8, the NPPM_SAVESESSION handler in PowerEditor/src/NppBigSwitch.cpp converts lParam to a sessionInfo pointer and dereferences its nbFile, files, and sessionFilePathName members without checking for null. A process running at the same or a higher Windows integrity level on the same desktop can send NPPM_SAVESESSION with a null lParam, immediately terminating Notepad++ and causing denial of service and loss of unsaved documents. This issue is fixed in version 8.9.8.

CVSS v3
5.5
EG Score
5.5MEDIUMmedium confidence
EG Risk
41
EG Risk 41/100CISA 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
Severity55% × 45%
Exploitation40% × 40%
Automatability0% × 15%
CISA SSVC: Track at low or medium mission impact; Track* at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
4th
KEV
Not listed

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

A fix is available. Apply it within your standard update timelines.

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 22, 2026

Last Modified

September 23, 2026

Advisory Details (4)

Auto-updated Sep 22, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit, github_release.
generic

Notepad++ v8.9.8 release | Notepad++

https://notepad-plus-plus.org/news/v898-released
github_release Patch Available

Notepad++ release 8.9.8

Patch available: notepad-plus-plus/notepad-plus-plus v8.9.8

https://github.com/notepad-plus-plus/notepad-plus-plus/releases/tag/v8.9.8
github_commit

commit 8b33f52e7aa4 (notepad-plus-plus/notepad-plus-plus)

Fix landed in notepad-plus-plus/notepad-plus-plus commit 8b33f52e7aa4 — awaiting tagged release

https://github.com/notepad-plus-plus/notepad-plus-plus/commit/8b33f52e7aa488b1222d3cfce5903a38dd63101f
github Patch Available🟡 PoC Available

Null pointer dereference in NPPM_SAVESESSION message handler causes crash (DoS) · Advisory · notepad-plus-plus/notepad-plus-plus · GitHub

https://github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-j85c-6wc9-p98p

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 22× 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. 2026-10-04 05:20 UTCEG score recompute
  2. 2026-10-03 04:17 UTCEG score recompute
  3. 2026-10-02 17:57 UTCEPSS rescore
  4. 2026-10-02 03:13 UTCEG score recompute
  5. 2026-10-01 19:50 UTCEPSS rescore
  6. 2026-10-01 02:08 UTCEG score recompute
  7. 2026-09-30 15:04 UTCEPSS rescore
  8. 2026-09-30 01:04 UTCEG score recompute
  9. 2026-09-29 00:00 UTCEG score recompute
  10. 2026-09-28 13:52 UTCEPSS rescore
  11. 2026-09-27 22:56 UTCEG score recompute
  12. 2026-09-27 13:48 UTCEPSS rescore
  13. 2026-09-26 21:51 UTCEG score recompute
  14. 2026-09-26 15:59 UTCEPSS rescore
  15. 2026-09-24 19:41 UTCEG score recompute
  16. 2026-09-24 14:04 UTCEPSS rescore
  17. 2026-09-23 18:37 UTCEG score recompute
  18. 2026-09-23 17:54 UTCEPSS rescore
  19. 2026-09-22 18:32 UTCEG score recompute
  20. 2026-09-22 17:48 UTCEG score recompute
  21. 2026-09-22 17:25 UTCEG score recompute
  22. 2026-09-22 17:23 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-86056?
CVE-2026-86056 is a medium vulnerability published on September 22, 2026. Notepad++ is a free and open-source source code editor. Prior to 8.9.8, the NPPMSAVESESSION handler in PowerEditor/src/NppBigSwitch.cpp converts lParam to a sessionInfo pointer and dereferences its nbFile, files, and sessionFilePathName members without checking for null. A process running at the…
When was CVE-2026-86056 disclosed?
CVE-2026-86056 was first published on September 22, 2026, with the most recent update on September 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-86056 actively exploited?
CVE-2026-86056 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (4th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-86056?
CVE-2026-86056 has a CVSS base score of 5.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-86056?
A fix for CVE-2026-86056 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

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