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TI-2026-42173 Aliases CVE-2026-58593GHSA-8m27-grg5-27vj

NodeBB - ActivityPub Author Spoofing via Unvalidated attributedTo Mapped to Local User

Priority HIGH 77CWE-290Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Security bypass
Confidentiality · integrity · availability
None · High · None
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-290.

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.0029 21st percentileScored 2026-11-07
Public exploit Yes 2 exploit referencesTagged by the CNA and NVD
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
NodeBBNodeBB4.13.2 and later—No fix listedCNA
  • NodeBB VendorNodeBB Affected 4.13.2 and later Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:nodebb:nodebb:*:*:*:*:*:*:*:*up to 4.13.2VulnerableNodeBB
  • cpe:2.3:a:nodebb:nodebb:*:*:*:*:*:*:*:* Versions up to 4.13.2 Vulnerable ·NodeBB

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-58593
  2. 2026-10-03 Alias added: GHSA-8m27-grg5-27vj

References

Exploit 2

  • TI-2023-23124 A remote code execution (RCE) vulnerability in the xmlrpc.php endpoint of NodeBB Inc… CVSS 3.1CRITICAL 9.8
  • TI-2022-22808 Account takeover via prototype vulnerability CVSS 3.1CRITICAL 9.8
  • TI-2025-32286 NodeBB v4.3.0 is vulnerable to SQL injection in its search-categories API endpoint… CVSS 3.1HIGH 8.6
  • TI-2023-14416 NodeBB Pre-Authentication Denial-of-Service CVSS 3.1HIGH 7.5
  • TI-2022-16499 Account takeover via SSO plugins in NodeBB CVSS 3.1HIGH 8.8
  • TI-2025-21119 Cross-Site Scripting (XSS) vulnerability in NodeBB v4.0.4 and before allows remote… CVSS 3.1MEDIUM 6.1
See all 19 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences