CVE-2026-63115

תיאור (מקור, אנגלית)

ActivityPub is a multi-tenant ActivityPub server for Ghost, built with Fedify. From 1.0.0 until 1.2.6, the `Undo` handler allows a remote federated server to cause the service to act on a `follow` or `repost` as though the activity came from a different account. This permits removal of an existing `follow` relationship or `repost` belonging to another account without that account's involvement. No private data is exposed and content is not modified; the affected relationships can be re-established. Services proxying to Ghost's hosted ActivityPub server have already been updated, while self-hosted services require an updated image and redeployment. This issue is fixed in version 1.2.6.

מדדים

CVSS 3.1

5.3 (MEDIUM) מקור הציון: CNA CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS — סבירות ניצול

0% (אחוזון 000) נכון ל-31/10/2026

CWE

CWE-290, CWE-345, CWE-863

קישורים

• https://github.com/TryGhost/ActivityPub/commit/1526f540b983da97750b380868a210e‮…
• https://github.com/TryGhost/ActivityPub/pull/1929
• https://github.com/TryGhost/ActivityPub/releases/tag/v1.2.6
• https://github.com/TryGhost/ActivityPub/security/advisories/GHSA-mm4q-93gr-5mwc