Nixpkgs security tracker

Untriaged

Permalink CVE-2026-42180

6.3 MEDIUM

CVSS version (CVSS): 3.1
Attack Vector (AV): Network (N)
Attack Complexity (AC): Low (L)
Privileges Required (PR): Low (L)
User Interaction (UI): None (N)
Scope (S): Unchanged (U)
Confidentiality (C): Low (L)
Integrity (I): Low (L)
Availability (A): Low (L)
Modified Attack Vector (MAV): Network (N)
Modified Attack Complexity (MAC): Low (L)
Modified Privileges Required (MPR): Low (L)
Modified User Interaction (MUI): None (N)
Modified Confidentiality (MC): Low (L)
Modified Scope (MS): Unchanged (U)
Modified Integrity (MI): Low (L)
Modified Availability (MA): Low (L)

created 4 months, 1 week ago Activity log

Created suggestion 4 months, 1 week ago

Lemmy: SSRF in /api/v3/post via Webmention dispatch

Lemmy is a link aggregator and forum for the fediverse. Prior to version 0.19.18, Lemmy allows an authenticated low-privileged user to create a link post through POST /api/v3/post. When a post is created in a public community, the backend asynchronously sends a Webmention to the attacker-controlled link target. The submitted URL is checked for syntax and scheme, but the audited code path does not reject loopback, private, or link-local destinations before the Webmention request is issued. This lets a normal user trigger server-side HTTP requests toward internal services. This issue has been patched in version 0.19.18.