Improper access control in Mastodon - CVE-2024-37903
Published: July 4, 2024 / Updated: April 23, 2026
Vulnerability identifier: #VU126974
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2024-37903
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Mastodon
Affected software:
Mastodon
Mastodon
Detailed vulnerability description
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to improper access control in audience extension handling for existing posts when processing crafted activities. A remote attacker can send specific crafted activities to disclose sensitive information.
Exploitation requires knowledge of the protocol identifier for the target message and control of an account on a Mastodon server that already has legitimate access to that message.
How to mitigate CVE-2024-37903
Install security update from vendor's website.