CVEvulnerability

CVE-2026-55103

8.6 HIGH Published 2026-10-15 Modified 2026-10-28 Official page ↗
Status
Deferred
Published
2026-10-15
Last modified
2026-10-28
Assigner
[email protected]
CVSS 3.1 ([email protected])
8.6 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
Weaknesses
CWE-345, CWE-863

Description

Discourse ActivityPub adds ActivityPub support to Discourse. Prior to commit 1c8518b0f2abdf31cbea3e0b242f74d8994a9ba5, inbound ActivityPub processing does not sufficiently verify that the actor authenticated by the signed request matches the Activity actor and owns the referenced federated post. A remote attacker can exploit these missing identity and ownership checks to edit, delete, or reply to federated posts without the required permissions. This vulnerability is fixed with commit 1c8518b0f2abdf31cbea3e0b242f74d8994a9ba5.

Related

Weakness · CWE (2)

  • CWE-345 Insufficient Verification of Data Authenticity weakness
  • CWE-863 Incorrect Authorization weakness

References