{"id":"CVE-2026-54741","title":"Lemmy is a link aggregator and forum for the fediverse","summary":"Lemmy is a link aggregator and forum for the fediverse. Prior to 0.19.19 and 1.0.0-alpha.18, Lemmy blocks new private messages from a sender after the recipient blocks that sender, but the edit path skips the same block check. create_pri…","severity":"none","cwe":["CWE-862"],"published":"2026-08-19","updated":"2026-09-09","sourceUpdated":"2026-09-09T21:15:59.613","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-54741","references":[{"url":"https://github.com/LemmyNet/lemmy/commit/051b317c9d14b91972bb372c67f319d6900beb93","label":"security-advisories@github.com"},{"url":"https://github.com/LemmyNet/lemmy/commit/2d169d630b86b9351e4b1dca451214b741f46150","label":"security-advisories@github.com"},{"url":"https://github.com/LemmyNet/lemmy/pull/6472","label":"security-advisories@github.com"},{"url":"https://github.com/LemmyNet/lemmy/pull/6476","label":"security-advisories@github.com"},{"url":"https://github.com/LemmyNet/lemmy/releases/tag/0.19.19","label":"security-advisories@github.com"},{"url":"https://github.com/LemmyNet/lemmy/releases/tag/1.0.0-alpha.18","label":"security-advisories@github.com"},{"url":"https://github.com/LemmyNet/lemmy/security/advisories/GHSA-46g9-847m-qf8r","label":"security-advisories@github.com"},{"url":"https://github.com/LemmyNet/lemmy/security/advisories/GHSA-46g9-847m-qf8r","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"tags":["nvd"],"epss":0.0045,"epssPercentile":0.38484,"ingestedAt":"2026-09-09T21:22:45.544Z","slug":"CVE-2026-54741","body":"## Overview\n\nLemmy is a link aggregator and forum for the fediverse. Prior to 0.19.19 and 1.0.0-alpha.18, Lemmy blocks new private messages from a sender after the recipient blocks that sender, but the edit path skips the same block check. create_private_message checks the recipient's block list with PersonActions::read_block before inserting a message, while edit_private_message in crates/api/api_crud/src/private_message/update.rs only checks that the caller is orig_private_message.creator_id. The update then writes new content and returns the modified PrivateMessageView without consulting the recipient's block list, allowing a blocked sender to keep changing an old message that the recipient can still see and providing a post-block harassment path. This issue is fixed in versions 0.19.19 and 1.0.0-alpha.18.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}