# CVE-2026-116208: YesWiki 4.6.2 before 4.7.0 Missing Authorization in ActivityPub syncActorPosts

Status: published. Published: 2026-10-25. Updated: 2026-11-03.

YesWiki from 4.6.2 before 4.7.0 contains a missing authorization vulnerability in ActivityPubService::syncActorPosts that lets malicious ActivityPub servers manipulate other actors' mirrored entries. Attackers can serve a poisoned outbox with cross-actor Delete, Update, or Create activities during admin-initiated sync to delete, overwrite, forge, or mass-delete entries.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- YesWiki / yeswiki: ≥ 4.6.2; < 4.7.0 (affected, semver); 4.7.0 (unaffected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 7.2 (high); CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 8.1 (high); CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H; source: CNA: VulnCheck

- CVSS 4.0: 7.2 (high); CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X; source: NVD: disclosure@vulncheck.com

- CVSS 3.1: 8.1 (high); CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H; source: NVD: disclosure@vulncheck.com

- CISA KEV: No listing in collected sources

- EPSS: 0.24% as of 2026-11-03; percentile 15.39%

- SSVC: exploitation poc; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-862

## Exploit evidence

- exploit: https://github.com/YesWiki/yeswiki/security/advisories/GHSA-cr64-h6xp-9g2j (ADP: CISA-ADP)

## References

- https://github.com/YesWiki/yeswiki/security/advisories/GHSA-cr64-h6xp-9g2j (CNA: VulnCheck; vendor-advisory)

- https://www.vulncheck.com/advisories/yeswiki-4.6.2-before-4.7.0-missing-authorization-in-activitypub-syncactorposts (CNA: VulnCheck; third-party-advisory)

- https://github.com/YesWiki/yeswiki/security/advisories/GHSA-cr64-h6xp-9g2j (ADP: CISA-ADP; exploit)

- https://github.com/YesWiki/yeswiki/security/advisories/GHSA-cr64-h6xp-9g2j (disclosure@vulncheck.com)

- https://www.vulncheck.com/advisories/yeswiki-4.6.2-before-4.7.0-missing-authorization-in-activitypub-syncactorposts (disclosure@vulncheck.com)

- https://github.com/YesWiki/yeswiki/security/advisories/GHSA-cr64-h6xp-9g2j (134c704f-9b21-4f2e-91b3-4a467353bcc0)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-116208; retrieved 2026-11-03; source updated 2026-11-03

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-116208; retrieved 2026-11-03; source updated 2026-11-03

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-116208; retrieved 2026-11-03; source updated Not reported

Revision: c46976798026e023d7f1ac57b42b37dafbbc0edb0606e47fbed7a56a373ead1e

Canonical: https://y2.dev/cve/CVE-2026-116208

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.