{"cve":"CVE-2026-54741","nvd":{"published":"2026-08-19T21:16:58.510","modified":"2026-09-09T21:15:59.613","status":"Deferred","description":"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_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.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","score":5.3},"cvss_v3":null,"cwes":["CWE-862"],"references":["https://github.com/LemmyNet/lemmy/commit/051b317c9d14b91972bb372c67f319d6900beb93","https://github.com/LemmyNet/lemmy/commit/2d169d630b86b9351e4b1dca451214b741f46150","https://github.com/LemmyNet/lemmy/pull/6472","https://github.com/LemmyNet/lemmy/pull/6476","https://github.com/LemmyNet/lemmy/releases/tag/0.19.19"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:49:38.260478770+00:00"},"epss":{"cve":"CVE-2026-54741","score":0.00484,"percentile":0.41685,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}