CVE-2026-52769

HIGHPre-NVD 8.38.3—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 78% 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
8.3EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.3Exploit: 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. From version 4.6.2 to before version 4.6.6, the POST /api/forms/{formId}/actor/inbox route - exposed publicly with acl:"public" - accepts an HTTP Signature header whose keyId parameter is a URL. HttpSignatureService::verifySignature() parses the header and immediately makes a server-side HTTP GET to that URL, before any cryptographic verification or URL validation. An unauthenticated remote attacker can therefore make YesWiki issue arbitrary outbound HTTP requests to any host the server can reach - internal services, cloud-metadata endpoints (169.254.169.254), intranet-only admin panels, etc. - and read enough back via timing and error-message oracles to scan ports, enumerate services, and (on a real cloud instance) reach IAM metadata. The only deployment-side precondition is that ActivityPub be enabled on at least one Bazar form. This issue has been patched in version 4.6.6.

CVSS v3
8.3
EG Score
8.3(medium)
EG Risk
68(Attend)
EG Risk 68/100SSVC: 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
Severity83% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
22%
KEV
Not listed

Published

July 9, 2026

Last Modified

September 8, 2026

Advisory Details (3)

Auto-updated Sep 4, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_release, github_commit.
github_commit Patch Available

commit 87e627f33e79 (YesWiki/yeswiki)

Patch available: YesWiki/yeswiki v4.6.6 (contains commit 87e627f33e79)

http://github.com/YesWiki/yeswiki/commit/87e627f33e79879827a3669fee2aa1244612c487
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 Patch Available🟡 PoC Available

Unauthenticated Server-Side Request Forgery via ActivityPub `Signature.keyId` · Advisory · YesWiki/yeswiki · GitHub

https://github.com/YesWiki/yeswiki/security/advisories/GHSA-vw42-752g-5mrp

Vendor Advisories for CVE-2026-52769(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/yeswikiv4.6.2, v4.6.3, v4.6.4, v4.6.54.6.6—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 6× in last 7d / 18× 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. 2026-09-12 16:00 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. 2026-09-08 22:53 UTCEG score recompute
  12. 2026-09-08 22:01 UTCEPSS rescore
  13. 2026-09-08 16:14 UTCEG score recompute
  14. 2026-09-07 16:01 UTCEPSS rescore
  15. 2026-09-06 13:59 UTCEG score recompute
  16. 2026-09-06 13:47 UTCEPSS rescore
  17. 2026-09-05 22:30 UTCEG score recompute
  18. 2026-09-05 00:19 UTCEG score recompute
  19. 2026-07-30 21:50 UTCEG score recompute
  20. 2026-07-26 12:17 UTCEG score recompute
  21. 2026-07-23 03:19 UTCEG score recompute
  22. 2026-07-09 21:46 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-52769?
CVE-2026-52769 is a high vulnerability published on July 9, 2026. YesWiki is a wiki system written in PHP. From version 4.6.2 to before version 4.6.6, the POST /api/forms/{formId}/actor/inbox route - exposed publicly with acl:"public" - accepts an HTTP Signature header whose keyId parameter is a URL. HttpSignatureService::verifySignature() parses the header and…
When was CVE-2026-52769 disclosed?
CVE-2026-52769 was first published in the National Vulnerability Database on July 9, 2026, with the most recent update on September 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-52769 actively exploited?
CVE-2026-52769 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 77.5% of all scored CVEs.
What is the CVSS score of CVE-2026-52769?
CVE-2026-52769 has a CVSS v3 base score of 8.3 (NVD).
How do I remediate CVE-2026-52769?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-52769, 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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