← Vulnerability feed

Vulnerability record · CVE-2024-37903 · published 5 July 2024

CVE-2024-37903: Joinmastodon mastodon missing authorization vulnerability

Joinmastodon · Mastodon

Mastodon is a self-hosted, federated microblogging platform. Starting in version 2.6.0 and prior to versions 4.1.18 and 4.2.10, by crafting specific activities, an attacker can extend the audience of a post they do not own to other Mastodon users on a target server, thus gaining access to the contents of a post not intended for them. Versions 4.1.18 and 4.2.10 contain a patch for this issue.

8.2 CVSS 3.1 High EPSS 0.53% · top 57.7% CWE-862 · Missing authorization
8.2CVSS 3.1 base score
0.53%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
10References
17 Jun 2026Last modified by NVD

Description

Mastodon is a self-hosted, federated microblogging platform. Starting in version 2.6.0 and prior to versions 4.1.18 and 4.2.10, by crafting specific activities, an attacker can extend the audience of a post they do not own to other Mastodon users on a target server, thus gaining access to the contents of a post not intended for them. Versions 4.1.18 and 4.2.10 contain a patch for this issue.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/mastodon/mastodon/commit/a1c7aae28aecf06659c5b18cfa131b37cd1512a3 Patch
https://github.com/mastodon/mastodon/commit/d4bf22b632ea8b1174375c4966a6768ab66393b6 Patch
https://github.com/mastodon/mastodon/releases/tag/v4.1.18 Release Notes
https://github.com/mastodon/mastodon/releases/tag/v4.2.10 Release Notes
https://github.com/mastodon/mastodon/security/advisories/GHSA-xjvf-fm67-4qc3 Vendor Advisory
https://github.com/mastodon/mastodon/commit/a1c7aae28aecf06659c5b18cfa131b37cd1512a3 Patch
https://github.com/mastodon/mastodon/commit/d4bf22b632ea8b1174375c4966a6768ab66393b6 Patch
https://github.com/mastodon/mastodon/releases/tag/v4.1.18 Release Notes
https://github.com/mastodon/mastodon/releases/tag/v4.2.10 Release Notes
https://github.com/mastodon/mastodon/security/advisories/GHSA-xjvf-fm67-4qc3 Vendor Advisory

Track CVE-2024-37903 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.9CVE-2023-36460Joinmastodon mastodon path traversal vulnerabilityMastodon is a free, open-source social network server based on ActivityPub. Starting in version 3.5.0 and prior to versions 3.5.9, 4.0.5, and 4.1.3, …EPSS 40%9.8CVE-2024-23832Joinmastodon mastodon authentication bypass by spoofing vulnerabilityMastodon is a free, open-source social network server based on ActivityPub Mastodon allows configuration of LDAP for authentication. Due to insuffici…EPSS 2.5%9.8CVE-2022-2166Joinmastodon mastodon improper restriction of authentication attempts vulnerabilityImproper Restriction of Excessive Authentication Attempts in GitHub repository mastodon/mastodon prior to 4.0.0.EPSS 1.1%9.8CVE-2022-24307Joinmastodon mastodon incorrect authorization vulnerabilityMastodon before 3.3.2 and 3.4.x before 3.4.6 has incorrect access control because it does not compact incoming signed JSON-LD activities. (JSON-LD si…EPSS 1.4%9.8CVE-2018-21018Joinmastodon mastodon insufficient session expiration vulnerabilityMastodon before 2.6.3 mishandles timeouts of incompletely established sessions.EPSS 2.6%8.2CVE-2026-41259Joinmastodon mastodon vulnerabilityMastodon is a free, open-source social network server based on ActivityPub. Prior to v4.5.9, v4.4.16, and v4.3.22, Mastodon allows restricting new us…EPSS 0.37%7.7CVE-2024-25623Joinmastodon mastodon unrestricted file upload vulnerabilityMastodon is a free, open-source social network server based on ActivityPub. Prior to versions 4.2.7, 4.1.15, 4.0.15, and 3.5.19, when fetching remote…EPSS 0.51%7.5CVE-2026-23962Joinmastodon mastodon allocation without limits vulnerabilityMastodon is a free, open-source social network server based on ActivityPub. Mastodon versions before v4.3.18, v4.4.12, and v4.5.5 do not have a limit…EPSS 0.55%

Source: NIST National Vulnerability Database (record CVE-2024-37903), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.