Is there a public exploit for CVE-2026-63115?

No public exploit for CVE-2026-63115 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-63115?

CVE-2026-63115 scores CVSS 5.3 (v3.1), rated medium. EPSS puts the chance of exploitation in the next 30 days at 0.14%.

What does CVE-2026-63115 affect?

CVE-2026-63115 affects TryGhost ActivityPub.

5.3 Medium

ActivityPub is a multi-tenant ActivityPub server for Ghost, built with Fedify.

CVE-2026-63115

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.

Assessment

CVSS: 5.3 (v3.1)
Severity: Medium
EPSS: 0.14% chance of exploitation in the next 30 days
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 30 October 2026
Last updated: 2 November 2026
Affected: TryGhost · ActivityPub
Assigner: GitHub_M

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

At the source

EUVD (ENISA)

References

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