CVE-2026-52778

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.6%, top 56% 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
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.8Exploit: 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, an unsafe execution vulnerability exists in the Bazar form field calculator (CalcField.php) of YesWiki. The application attempts to sanitize user-defined mathematical formulas using a complex recursive regular expression before passing them to the PHP eval() function. This implementation is inherently flawed: it is vulnerable to Regular Expression Denial of Service (ReDoS / Stack Overflow) which can crash the server, and it creates a high-risk architecture where any logic bypass directly results in arbitrary PHP code execution. Version 4.6.6 patches the issue.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
75(Attend)
EG Risk 75/100SSVC: 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
Severity98% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
1%
EPSS %ILE
44%
KEV
Not listed

Published

June 8, 2026

Last Modified

July 23, 2026

Advisory Details (3)

Auto-updated Aug 22, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_release, github.
github Patch Available🟡 PoC Available

Unsafe eval() in Formula Calculator - Remote Code Execution (RCE) & Denial of Service (DoS) · Advisory · YesWiki/yeswiki · GitHub

https://github.com/YesWiki/yeswiki/security/advisories/GHSA-px5m-h76g-p7p8
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 dd2bd8fb099d (YesWiki/yeswiki)

Patch available: YesWiki/yeswiki v4.6.6 (contains commit dd2bd8fb099d)

https://github.com/YesWiki/yeswiki/commit/dd2bd8fb099de0d21504bda8a810693b3fcb8e52

Vendor Advisories for CVE-2026-52778(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 10× in last 7d / 50× 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.

Showing the most recent 100 of 120 total refreshes for this CVE.

  1. 2026-08-25 13:49 UTCEPSS rescore
  2. 2026-08-25 01:16 UTCEG score recompute
  3. 2026-08-23 11:43 UTCEG score recompute
  4. 2026-08-23 00:19 UTCEPSS rescore
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  12. 2026-08-17 15:09 UTCEG score recompute
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  24. 2026-08-11 14:22 UTCEG score recompute
  25. 2026-08-11 01:34 UTCEG score recompute
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  1. 2026-08-11 00:00 UTCEPSS rescore
  2. 2026-08-09 17:43 UTCEG score recompute
  3. 2026-08-09 13:46 UTCEPSS rescore
  4. 2026-08-08 20:29 UTCEG score recompute
  5. 2026-08-08 16:37 UTCEPSS rescore
  6. 2026-08-07 18:59 UTCEG score recompute
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  8. 2026-08-06 13:47 UTCEPSS rescore
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  18. 2026-08-01 10:48 UTCEG score recompute
  19. 2026-08-01 04:16 UTCEPSS rescore
  20. 2026-07-31 04:50 UTCEG score recompute
  21. 2026-07-30 16:28 UTCEPSS rescore
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  23. 2026-07-29 06:14 UTCEG score recompute
  24. 2026-07-28 15:37 UTCEPSS rescore
  25. 2026-07-27 18:32 UTCEG score recompute
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  27. 2026-07-26 14:54 UTCEPSS rescore
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  29. 2026-07-25 14:18 UTCEPSS rescore
  30. 2026-07-24 14:18 UTCEPSS rescore
  31. 2026-07-23 14:18 UTCEPSS rescore
  32. 2026-07-23 03:19 UTCEG score recompute
  33. 2026-07-22 14:08 UTCEPSS rescore
  34. 2026-07-21 15:25 UTCEPSS rescore
  35. 2026-07-20 17:08 UTCEPSS rescore
  36. 2026-07-19 14:31 UTCEPSS rescore
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  38. 2026-07-19 02:29 UTCEPSS rescore
  39. 2026-07-18 10:04 UTCEPSS rescore
  40. 2026-07-16 17:03 UTCEPSS rescore
  41. 2026-07-15 16:57 UTCEPSS rescore
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  45. 2026-07-13 22:31 UTCEPSS rescore
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  48. 2026-07-12 05:46 UTCEPSS rescore
  49. 2026-07-11 08:27 UTCEPSS rescore
  50. 2026-07-11 08:27 UTCEPSS rescore
  51. 2026-07-09 19:10 UTCEPSS rescore
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  53. 2026-07-08 15:16 UTCEPSS rescore
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  55. 2026-07-07 13:46 UTCEPSS rescore
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  57. 2026-07-06 16:27 UTCEPSS rescore
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  66. 2026-06-28 14:07 UTCEPSS rescore
  67. 2026-06-28 04:56 UTCEPSS rescore
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  69. 2026-06-27 03:08 UTCEPSS rescore
  70. 2026-06-25 13:49 UTCEPSS rescore
  71. 2026-06-24 14:05 UTCEPSS rescore
  72. 2026-06-23 21:33 UTCEPSS rescore
  73. 2026-06-23 21:33 UTCEPSS rescore
  74. 2026-06-22 14:25 UTCEPSS rescore
  75. 2026-06-22 14:25 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-52778?
CVE-2026-52778 is a critical vulnerability published on June 8, 2026. YesWiki is a wiki system written in PHP. Prior to version 4.6.6, an unsafe execution vulnerability exists in the Bazar form field calculator (CalcField.php) of YesWiki. The application attempts to sanitize user-defined mathematical formulas using a complex recursive regular expression before…
When was CVE-2026-52778 disclosed?
CVE-2026-52778 was first published in the National Vulnerability Database on June 8, 2026, with the most recent update on July 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-52778 actively exploited?
CVE-2026-52778 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 55.8% of all scored CVEs.
What is the CVSS score of CVE-2026-52778?
CVE-2026-52778 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-52778?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-52778, 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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