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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-54742 Detail

Description

Lemmy is a link aggregator and forum for the fediverse. From 0.19.18 until 0.19.19 and 1.0.0-alpha.20, a community moderator can feature or unfeature posts in other communities through federated CollectionAdd and CollectionRemove activities using CollectionType::Featured. After verify_mod_action authorizes the actor against self.community(), the receive handlers in crates/apub/activities/src/community/collection_add.rs and crates/apub/activities/src/community/collection_remove.rs dereference self.object as an ApubPost and update featured_community without verifying that post.community_id equals community.id. A moderator can therefore target an unrelated post owned by another community, push it into featured feeds and listings, or undo another community's legitimate curation decision. This issue is fixed in versions 0.19.19 and 1.0.0-alpha.20.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  GitHub, Inc.
CVSS-B 5.1 MEDIUM
Vector:  CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/LemmyNet/lemmy/commit/108d78c592cc88bac2b0bf52ca6631be54f6fb23 GitHub, Inc.
https://github.com/LemmyNet/lemmy/commit/abe256243822526dcd4bca857f7c0adeb49944f5 GitHub, Inc.
https://github.com/LemmyNet/lemmy/pull/6500 GitHub, Inc.
https://github.com/LemmyNet/lemmy/pull/6501 GitHub, Inc.
https://github.com/LemmyNet/lemmy/releases/tag/0.19.19 GitHub, Inc.
https://github.com/LemmyNet/lemmy/releases/tag/1.0.0-alpha.20 GitHub, Inc.
https://github.com/LemmyNet/lemmy/security/advisories/GHSA-gwfj-h8r7-792v GitHub, Inc.
https://join-lemmy.org/news/2026-06-09_-_Lemmy_Release_v0.19.19 GitHub, Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-863 Incorrect Authorization GitHub, Inc.  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-54742
NVD Published Date:
08/19/2026
NVD Last Modified:
08/19/2026
Source:
GitHub, Inc.