CVE-2026-55103 (GCVE-0-2026-55103)
Vulnerability from cvelistv5
Published
2026-10-15 17:05
Modified
2026-10-28 20:15
CWE
  • CWE-345 - Insufficient Verification of Data Authenticity
  • CWE-863 - Incorrect Authorization
Summary
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.
Impacted products
Vendor Product Version
discourse discourse-activity-pub Version: < 1c8518b0f2abdf31cbea3e0b242f74d8994a9ba5
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  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
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