CVE-2026-58593

Summary

NodeBB does not bind the claimed author of an inbound ActivityPub object to the authenticated remote actor. The inbound middleware verifies the HTTP-signature actor and checks the origin of object.id, but never validates that attributedTo corresponds to the sender. In the object mock, attributedTo is used directly as a uid, and actors.assert silently ignores numeric identifiers (filtering them out without re-deriving the uid), so a federated remote actor can set attributedTo to a bare numeric value such as 1 and have the resulting post or private message created with that local uid as author, including the administrator account. This lets a remote attacker forge posts and direct messages attributed to arbitrary local users. Requires the ActivityPub/federation feature to be enabled.

Affected Software

VendorProductVersion RangeStatus
NodeBBNodeBB4.13.2affected

Weaknesses

  • CWE-345: Insufficient Verification of Data Authenticity
  • CWE-290: Authentication Bypass by Spoofing

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: yes
    • Technical Impact: partial

References