CVE-2026-91751

HIGHPre-NVD 8.38.3—
EchelonGraph scoreHIGH confidence

Score 8.3 from GitHub Security Advisory (severity: HIGH) published 2026-09-15. the CNA's CVSS baseline 8.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:vulncheck, epss, ghsa
Trending — 3 sources updated this weekElevated
8.3EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 8.3Exploit: Elevated riskExposed: 0

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

Flextype CMS through 1.0.0-alpha.3 fails to properly validate id and new_id parameters in the Entries REST API, allowing API token holders to read, create, or overwrite files outside the entries directory. Attackers can use traversal sequences in API requests to escape the project entries directory and manipulate arbitrary files and directories on the filesystem.

CVSS v3
8.3
EG Score
8.3(high)
EG Risk
53(Track*)
EG Risk 53/100SSVC: 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
Severity83% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Watch closely — could escalate to Attend.
EPSS PROB
1%
EPSS %ILE
43%
KEV
Not listed

Published

September 15, 2026

Last Modified

September 24, 2026

Advisory Details (4)

Auto-updated Sep 15, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic

Flextype CMS through 1.0.0-alpha.3 Path Traversal via Entries REST API | Advisories | VulnCheck

https://www.vulncheck.com/advisories/flextype-cms-through-1.0.0-alpha.3-path-traversal-via-entries-rest-api
generic

flextype/src/flextype/core/Entries/Entries.php at v1.0.0-alpha.3 · flextype/flextype · GitHub

https://github.com/flextype/flextype/blob/v1.0.0-alpha.3/src/flextype/core/Entries/Entries.php#L856-L906
generic

GitHub - flextype/flextype: Modern Open Source Flat Files Content Management System. · GitHub

https://github.com/flextype/flextype
generic🟡 PoC Available

Path Traversal in Flextype Entries REST API · Issue #596 · flextype/flextype · GitHub

https://github.com/flextype/flextype/issues/596

Vendor Advisories for CVE-2026-91751(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 26× in last 7d / 46× 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. 2026-09-25 03:29 UTCGHSA enrichment
  2. 2026-09-24 14:53 UTCEG score recompute
  3. 2026-09-24 14:53 UTCGHSA enrichment
  4. 2026-09-24 14:04 UTCEPSS rescore
  5. 2026-09-24 04:30 UTCEG score recompute
  6. 2026-09-24 04:30 UTCGHSA enrichment
  7. 2026-09-23 17:54 UTCEPSS rescore
  8. 2026-09-23 15:53 UTCGHSA enrichment
  9. 2026-09-23 03:17 UTCEG score recompute
  10. 2026-09-23 03:17 UTCGHSA enrichment
  11. 2026-09-22 16:01 UTCEPSS rescore
  12. 2026-09-22 14:41 UTCGHSA enrichment
  13. 2026-09-22 02:05 UTCEG score recompute
  14. 2026-09-22 02:05 UTCGHSA enrichment
  15. 2026-09-21 21:09 UTCEPSS rescore
  16. 2026-09-21 13:28 UTCGHSA enrichment
  17. 2026-09-21 00:52 UTCEG score recompute
  18. 2026-09-21 00:52 UTCGHSA enrichment
  19. 2026-09-20 20:16 UTCEPSS rescore
  20. 2026-09-20 12:15 UTCGHSA enrichment
  21. 2026-09-19 23:36 UTCEG score recompute
  22. 2026-09-19 23:36 UTCGHSA enrichment
  23. 2026-09-19 10:59 UTCGHSA enrichment
  24. 2026-09-18 22:23 UTCEG score recompute
  25. 2026-09-18 22:23 UTCGHSA enrichment
Show 21 more
  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 09:47 UTCGHSA enrichment
  3. 2026-09-17 21:11 UTCEG score recompute
  4. 2026-09-17 21:11 UTCGHSA enrichment
  5. 2026-09-17 19:32 UTCEPSS rescore
  6. 2026-09-17 08:35 UTCGHSA enrichment
  7. 2026-09-16 19:58 UTCEG score recompute
  8. 2026-09-16 19:58 UTCGHSA enrichment
  9. 2026-09-16 14:09 UTCEPSS rescore
  10. 2026-09-16 08:48 UTCEG score recompute
  11. 2026-09-16 08:48 UTCGHSA enrichment
  12. 2026-09-16 05:15 UTCEPSS rescore
  13. 2026-09-15 19:38 UTCEG score recompute
  14. 2026-09-15 19:38 UTCGHSA enrichment
  15. 2026-09-15 19:13 UTCEG score recompute
  16. 2026-09-15 19:13 UTCGHSA enrichment
  17. 2026-09-15 14:04 UTCEG score recompute
  18. 2026-09-15 14:04 UTCGHSA enrichment
  19. 2026-09-15 01:27 UTCEG score recompute
  20. 2026-09-15 00:45 UTCEG score recompute
  21. 2026-09-15 00:44 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-91751?
CVE-2026-91751 is a high vulnerability published on September 15, 2026. Flextype CMS through 1.0.0-alpha.3 fails to properly validate id and new_id parameters in the Entries REST API, allowing API token holders to read, create, or overwrite files outside the entries directory. Attackers can use traversal sequences in API requests to escape the project entries directory…
When was CVE-2026-91751 disclosed?
CVE-2026-91751 was first published in the National Vulnerability Database on September 15, 2026, with the most recent update on September 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-91751 actively exploited?
CVE-2026-91751 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 57.1% of all scored CVEs.
What is the CVSS score of CVE-2026-91751?
CVE-2026-91751 has a CVSS v4.0 base score of 8.3 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-91751?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-91751, 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

Explore the affected products and dependency analysis for CVE-2026-91751

Explore →

Is Your Infrastructure Affected by CVE-2026-91751?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs