CVE-2026-88418

HIGHPre-NVD 8.88.8—
EchelonGraph scoreHIGH confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-09-22. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this weekElevated
8.8EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 8.8Exploit: Elevated riskExposed services: Not assessed

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

CMSimple 5.24 ships with CSRF protection disabled by default, which turns csrfProtection() into a no-op on every state-changing admin request, and it does not send the csrf_token hidden field in admin forms. Because administrator authentication is cookie-only and no CSRF token is enforced, an unauthenticated attacker can induce a logged-in administrator's browser to issue a forged content-save request with a text payload containing a scripting marker. The marker is stored verbatim into content/content.php; on every subsequent page view evaluate_cmsimple_scripting() (functions.php) executes the marker body with PHP eval() — for all visitors, including unauthenticated ones. This yields persistent remote code execution on the web server.

CVSS v3
8.8
EG Score
8.8HIGHhigh confidence
EG Risk
56
EG Risk 56/100CISA 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
Severity88% × 45%
Exploitation40% × 40%
Automatability0% × 15%
CISA SSVC: Track at low, Track* at medium and Attend at high mission impact.
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
EPSS PROB
0.3%
EPSS %ILE
15th
KEV
Not listed

CISA SSVCTrack at low, Track* at medium and Attend at high mission impact.

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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 26, 2026

Advisory Details (1)

Auto-updated Sep 25, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic🟡 PoC Available

Cross-Site Request Forgery (CSRF protection disabled by default) leading to persistent stored code injection / remote code execution in CMSimple 5.24 · Issue #5 · 15536818056/CVE · GitHub

https://github.com/15536818056/CVE/issues/5

Vendor Advisories for CVE-2026-88418(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 / 48× 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. 2026-10-05 07:03 UTCEG score recompute
  2. 2026-10-05 07:03 UTCGHSA enrichment
  3. 2026-10-04 23:22 UTCEPSS rescore
  4. 2026-10-04 19:33 UTCGHSA enrichment
  5. 2026-10-04 08:04 UTCGHSA enrichment
  6. 2026-10-03 20:33 UTCEG score recompute
  7. 2026-10-03 20:32 UTCGHSA enrichment
  8. 2026-10-03 09:03 UTCGHSA enrichment
  9. 2026-10-02 21:29 UTCEG score recompute
  10. 2026-10-02 21:29 UTCGHSA enrichment
  11. 2026-10-02 09:55 UTCGHSA enrichment
  12. 2026-10-01 22:26 UTCEG score recompute
  13. 2026-10-01 22:25 UTCGHSA enrichment
  14. 2026-10-01 19:51 UTCEPSS rescore
  15. 2026-10-01 10:50 UTCGHSA enrichment
  16. 2026-09-30 23:21 UTCEG score recompute
  17. 2026-09-30 23:20 UTCGHSA enrichment
  18. 2026-09-30 15:04 UTCEPSS rescore
  19. 2026-09-30 11:49 UTCGHSA enrichment
  20. 2026-09-30 00:20 UTCEG score recompute
  21. 2026-09-30 00:20 UTCGHSA enrichment
  22. 2026-09-29 08:55 UTCEG score recompute
  23. 2026-09-29 08:55 UTCGHSA enrichment
  24. 2026-09-28 21:26 UTCEG score recompute
  25. 2026-09-28 21:26 UTCGHSA enrichment
Show 23 more
  1. 2026-09-28 13:52 UTCEPSS rescore
  2. 2026-09-28 09:56 UTCGHSA enrichment
  3. 2026-09-27 22:27 UTCEG score recompute
  4. 2026-09-27 22:27 UTCGHSA enrichment
  5. 2026-09-27 13:48 UTCEPSS rescore
  6. 2026-09-27 10:58 UTCGHSA enrichment
  7. 2026-09-26 23:29 UTCEG score recompute
  8. 2026-09-26 23:28 UTCGHSA enrichment
  9. 2026-09-26 15:59 UTCEPSS rescore
  10. 2026-09-26 11:55 UTCEG score recompute
  11. 2026-09-26 11:54 UTCGHSA enrichment
  12. 2026-09-26 00:23 UTCEG score recompute
  13. 2026-09-26 00:23 UTCGHSA enrichment
  14. 2026-09-25 23:35 UTCEG score recompute▲ 8.80
  15. 2026-09-25 23:34 UTCGHSA enrichment
  16. 2026-09-25 23:34 UTCMITRE cvelistV5CVSS v3 → 8.8 · severity → HIGH
  17. 2026-09-24 21:37 UTCEG score recompute
  18. 2026-09-24 21:37 UTCGHSA enrichment
  19. 2026-09-24 14:04 UTCEPSS rescore
  20. 2026-09-23 17:54 UTCEPSS rescore
  21. 2026-09-22 20:32 UTCNVD update
  22. 2026-09-22 19:38 UTCEG score recompute
  23. 2026-09-22 19:37 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-88418?
CVE-2026-88418 is a high vulnerability published on September 22, 2026. CMSimple 5.24 ships with CSRF protection disabled by default, which turns csrfProtection() into a no-op on every state-changing admin request, and it does not send the csrftoken hidden field in admin forms. Because administrator authentication is cookie-only and no CSRF token is enforced, an…
When was CVE-2026-88418 disclosed?
CVE-2026-88418 was first published on September 22, 2026, with the most recent update on September 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-88418 actively exploited?
CVE-2026-88418 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (15th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-88418?
CVE-2026-88418 has a CVSS v3.1 base score of 8.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-88418?
No fix for CVE-2026-88418 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-88418 are linked in the Vendor Advisories panel on this page.

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