CVE-2026-50128

MediumCVSS 5.3/10Last modified Jun 25, 2026

Description

Mastodon is a free, open-source social network server based on ActivityPub. From 4.3.0 until 4.5.11 and 4.4.18, Mastodon has a feature to let websites credit authors of their articles. To prevent false attribution claims, Mastodon uses the attributionDomains JSON-LD term, however, an error in how it is defined makes Linked Data Signatures on the toot:attributionDomains property ineffective. An attacker can arbitrarily modify the attributionDomains value of a legitimately signed Update activity and bypass Mastodon’s signature verification. This vulnerability is fixed in 4.5.11 and 4.4.18.

Metrics

CVSS 3.1 5.3/10CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Weakness enumeration

CWE-354

Affected software

No affected versions have been published.

Timeline

Published: Jun 24, 2026
Last modified: Jun 25, 2026
NVD status: Deferred

Related CVEs from 2026

CVE-2026-501297.5Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.5.11, 4.4.18, and 4.3.24, a DoS can be triggered by (CVE-2026-50135.3A vulnerability has been found in elecV2 elecV2P up to 3.8.3. Impacted is the function path.join of the file /store/:key. The manipulation o CVE-2026-501308.8Pi-hole is a DNS sinkhole that protects devices from unwanted content without installing any client-side software. From 6.0 to 6.4.2, a user CVE-2026-501318.6Fedify is a TypeScript library for building federated server apps powered by ActivityPub. Fedify previously addressed SSRF/internal network CVE-2026-501327.3Budibase is an open-source low-code platform. Prior to 3.39.0, `GET /api/chat-links/:instance/:token/handoff` is a public endpoint (no auth CVE-2026-501336.1Hugo is a static site generator. Prior to 0.162.0, Hugo accepts content files in several markup formats. Files mapped to the text/html media CVE-2026-501345.8Hugo is a static site generator. From 0.91.0 until 0.162.0, resources.GetRemote enforces security.http.urls on the URL it is called with, bu CVE-2026-501355.5Hugo is a static site generator. From 0.123.0 to 0.161.1, a regression made RootMappingFs.statRoot use Stat (follows symlinks) instead o CVE-2026-501365.3Budibase is an open-source low-code platform. Prior to 3.39.3, the application server exposes an unauthenticated endpoint that generates S3 CVE-2026-501379.4Budibase is an open-source low-code platform. Prior to 3.39.0, an anonymous attacker who knows or can enumerate a workspace id (app_...) and CVE-2026-501388.1goshs is a SimpleHTTPServer written in Go. Prior to version 2.1.0, when `goshs` is launched with WebDAV enabled (`-w`), the mode-restriction CVE-2026-501395.9goshs is a SimpleHTTPServer written in Go. Prior to version 2.1.0, `ShareHandler` reads the share token's `DownloadLimit` under `RLock`, rel