CVE-2026-52766

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 74% 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
Elevated
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.1Exploit: Elevated riskExposed: 0

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

YesWiki is a wiki system written in PHP. Prior to version 4.6.6, the {{erasespamedcomments}} wiki action (actions/EraseSpamedCommentsAction.php) accepts a suppr[] array from POST and deletes every wiki page whose tag appears in that array, with no authorization check anywhere in the action body or in the page-deletion path it invokes. Combined with YesWiki's allow-by-default action ACL model, any user who has page write access, which is the default for everyone (default_write_acl='*') on a fresh install can permanently delete arbitrary wiki pages, including the front page, admin pages, and pages owned by other users. This issue has been patched in version 4.6.6.

CVSS v3
9.1
EG Score
9.1(medium)
EG Risk
72(Attend)
EG Risk 72/100SSVC: Attend

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
Severity91% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
27%
KEV
Not listed

Published

July 9, 2026

Last Modified

September 9, 2026

Advisory Details (3)

Auto-updated Sep 15, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_release, github.
github Patch Available🟡 PoC Available

Unauthenticated arbitrary page deletion via `{{erasespamedcomments}}` action · Advisory · YesWiki/yeswiki · GitHub

https://github.com/YesWiki/yeswiki/security/advisories/GHSA-6x7x-gcmf-7r8x
github_release Patch Available

v4.6.6

Patch available: YesWiki/yeswiki v4.6.6

https://github.com/YesWiki/yeswiki/releases/tag/v4.6.6
github_commit Patch Available

commit ed5b548a705c (YesWiki/yeswiki)

Patch available: YesWiki/yeswiki v4.6.6 (contains commit ed5b548a705c)

https://github.com/YesWiki/yeswiki/commit/ed5b548a705c8091ba0282aaaba73ddda976abef

Vendor Advisories for CVE-2026-52766(1)

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

Affected Packages

(1 across 1 ecosystem)
Packagist(1)
PackageVulnerable rangeFixed inDependents
yeswiki/yeswiki4.2.3 ... v4.6.5 (31 versions)4.6.6—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 19× 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. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 05:35 UTCEG score recompute
  3. 2026-09-16 14:08 UTCEPSS rescore
  4. 2026-09-16 05:15 UTCEPSS rescore
  5. 2026-09-13 23:45 UTCEG score recompute
  6. 2026-09-13 16:47 UTCEPSS rescore
  7. 2026-09-13 08:17 UTCEG score recompute
  8. 2026-09-12 03:21 UTCEG score recompute
  9. 2026-09-11 14:53 UTCEPSS rescore
  10. 2026-09-10 09:35 UTCEPSS rescore
  11. 2026-09-09 17:34 UTCEG score recompute
  12. 2026-09-09 16:55 UTCEG score recompute
  13. 2026-09-08 22:53 UTCEG score recompute
  14. 2026-09-08 22:01 UTCEPSS rescore
  15. 2026-09-07 16:01 UTCEPSS rescore
  16. 2026-09-06 13:59 UTCEG score recompute
  17. 2026-09-06 13:47 UTCEPSS rescore
  18. 2026-09-05 22:30 UTCEG score recompute
  19. 2026-09-05 00:19 UTCEG score recompute
  20. 2026-07-30 12:34 UTCEG score recompute
  21. 2026-07-26 12:17 UTCEG score recompute
  22. 2026-07-23 03:19 UTCEG score recompute
  23. 2026-07-09 21:46 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-52766?
CVE-2026-52766 is a critical vulnerability published on July 9, 2026. YesWiki is a wiki system written in PHP. Prior to version 4.6.6, the {{erasespamedcomments}} wiki action (actions/EraseSpamedCommentsAction.php) accepts a suppr[] array from POST and deletes every wiki page whose tag appears in that array, with no authorization check anywhere in the action body or…
When was CVE-2026-52766 disclosed?
CVE-2026-52766 was first published in the National Vulnerability Database on July 9, 2026, with the most recent update on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-52766 actively exploited?
CVE-2026-52766 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 73.5% of all scored CVEs.
What is the CVSS score of CVE-2026-52766?
CVE-2026-52766 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-52766?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-52766, 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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