# CVE-2026-116825: YesWiki from 4.6.2 before 4.7.0 HTTP Signature Replay via ActivityPub Inbox

Status: published. Published: 2026-10-26. Updated: 2026-11-02.

YesWiki from 4.6.2 before 4.7.0 lacks replay protection in HttpSignatureService::verifySignature(), which never validates the Date header or tracks seen signatures. Attackers who capture a signed request to the /api/forms/{formId}/actor/inbox endpoint can replay it later to re-execute Delete, Update, Follow, or Undo actions.

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

- CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: 0.22% as of 2026-11-02; percentile 13.23%

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

- Weaknesses: CWE-294

## Exploit evidence

- exploit: https://github.com/YesWiki/yeswiki/security/advisories/GHSA-7m9j-h553-397x (ADP: CISA-ADP)

## References

- https://github.com/YesWiki/yeswiki/security/advisories/GHSA-7m9j-h553-397x (CNA: VulnCheck; vendor-advisory)

- https://www.vulncheck.com/advisories/yeswiki-from-4.6.2-before-4.7.0-http-signature-replay-via-activitypub-inbox (CNA: VulnCheck; third-party-advisory)

- https://github.com/YesWiki/yeswiki/security/advisories/GHSA-7m9j-h553-397x (ADP: CISA-ADP; exploit)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-116825; retrieved 2026-11-02; source updated 2026-11-02

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-116825; retrieved 2026-11-02; source updated Not reported

Revision: 4e3c7ffd35eac3ad93b1f11af82385cc21c47b48b9dfacd9278859b345f6ae3c

Canonical: https://y2.dev/cve/CVE-2026-116825

## 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.