CVE-2023-42450

Mastodon Server-Side Request Forgery vulnerability

State: Published
Severity: 5.4 Medium
Published: Sep 19, 2023
Updated: Jun 18, 2025
Reserved: Sep 8, 2023

Description

Mastodon is a free, open-source social network server based on ActivityPub. Starting in version 4.2.0-beta1 and prior to version 4.2.0-rc2, by crafting specific input, attackers can inject arbitrary data into HTTP requests issued by Mastodon. This can be used to perform confused deputy attacks if the server configuration includes `ALLOWED_PRIVATE_ADDRESSES` to allow access to local exploitable services. Version 4.2.0-rc2 has a patch for the issue.

Scores

CVSS	Score	Vector	Source
3.1	5.4 Medium	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N	GitHub_M

Weaknesses

CWE-918 Server-Side Request Forgery (SSRF)
CWE-113 Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')

Affected Products

Product	Versions
mastodonmastodon	>= 4.2.0-beta1, < 4.2.0-rc2Affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.