CVE-2026-54758

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 91% of all CVEs by exploit prediction. 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
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.8Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Notepad++ is a free and open-source source code editor. Prior to 8.9.7, the expandNppEnvironmentStrs function in PowerEditor/src/WinControls/StaticDialog/RunDlg/RunDlg.cpp copies a Notepad++ variable name between $( and ) into the fixed-size wchar_t str[MAX_PATH] stack buffer without bounding the m loop index, allowing a name of 260 or more characters to corrupt adjacent stack data, terminate the process through __report_gsfailure, and potentially execute code. This issue is fixed in version 8.9.7.

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
35(Track)
EG Risk 35/100SSVC: Track

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
Severity78% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
9%
KEV
Not listed

Published

August 17, 2026

Last Modified

August 17, 2026

Advisory Details (3)

Auto-updated Aug 17, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit, github_release.
github Patch Available🟡 PoC Available

Stack Buffer Overflow in expandNppEnvironmentStrs (CWE-121) · Advisory · notepad-plus-plus/notepad-plus-plus · GitHub

https://github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-gv94-327x-2gc5
github_release Patch Available

Notepad++ release 8.9.7

Patch available: notepad-plus-plus/notepad-plus-plus v8.9.7

https://github.com/notepad-plus-plus/notepad-plus-plus/releases/tag/v8.9.7
github_commit

commit 0a9527e9f714 (notepad-plus-plus/notepad-plus-plus)

Fix landed in notepad-plus-plus/notepad-plus-plus commit 0a9527e9f714 — awaiting tagged release

https://github.com/notepad-plus-plus/notepad-plus-plus/commit/0a9527e9f7140a2323e25d14e362b46ee0efc3db

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 21× 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. 2026-08-30 01:22 UTCEPSS rescore
  2. 2026-08-29 05:25 UTCEG score recompute
  3. 2026-08-28 21:41 UTCEPSS rescore
  4. 2026-08-27 01:25 UTCEG score recompute
  5. 2026-08-26 14:46 UTCEPSS rescore
  6. 2026-08-26 00:56 UTCEG score recompute
  7. 2026-08-25 13:49 UTCEPSS rescore
  8. 2026-08-25 00:39 UTCEG score recompute
  9. 2026-08-24 12:28 UTCEG score recompute
  10. 2026-08-22 11:47 UTCEG score recompute
  11. 2026-08-21 23:49 UTCEPSS rescore
  12. 2026-08-20 23:21 UTCEG score recompute
  13. 2026-08-20 22:55 UTCEPSS rescore
  14. 2026-08-19 23:05 UTCEG score recompute
  15. 2026-08-19 17:04 UTCEPSS rescore
  16. 2026-08-18 22:46 UTCEG score recompute
  17. 2026-08-18 13:48 UTCEPSS rescore
  18. 2026-08-17 22:22 UTCEG score recompute
  19. 2026-08-17 22:09 UTCEG score recompute
  20. 2026-08-17 20:20 UTCEG score recompute
  21. 2026-08-17 20:19 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-54758?
CVE-2026-54758 is a high vulnerability published on August 17, 2026. Notepad++ is a free and open-source source code editor. Prior to 8.9.7, the expandNppEnvironmentStrs function in PowerEditor/src/WinControls/StaticDialog/RunDlg/RunDlg.cpp copies a Notepad++ variable name between $( and ) into the fixed-size wchart str[MAXPATH] stack buffer without bounding the m…
When was CVE-2026-54758 disclosed?
CVE-2026-54758 was first published in the National Vulnerability Database on August 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-54758 actively exploited?
CVE-2026-54758 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 90.9% of all scored CVEs.
What is the CVSS score of CVE-2026-54758?
CVE-2026-54758 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2026-54758?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-54758, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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