Error Handling Vulnerability in Mastodon Social Network Server
CVE-2025-67500

3.7LOW

Key Information:

Vendor

Mastodon

Status
Mastodon
Vendor
CVE Published:
9 December 2025

What is CVE-2025-67500?

The Mastodon social network server has a flaw in its error handling mechanism that allows an attacker to ascertain the existence of specific statuses by manipulating the Accept-Language header. This vulnerability affects multiple versions of the server, enabling unauthorized status checks without revealing any content or additional information beyond the existence of the status. The issue has been patched in subsequent releases.

Affected Version(s)

mastodon < 4.2.28 < 4.2.28

mastodon >= 4.3.0-beta.1, < 4.3.15 < 4.3.0-beta.1, 4.3.15

mastodon >= 4.4.0-beta.1, < 4.4.10 < 4.4.0-beta.1, 4.4.10

References

https://github.com/mastodon/mastodon/security/advisories/...
x_refsource_CONFIRM
https://github.com/mastodon/mastodon/pull/37077/commits/9...
x_refsource_MISC

CVSS V3.1

Score:
3.7
Severity:
LOW
Confidentiality:
Low
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

JSON
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CVE-2025-67500 : Error Handling Vulnerability in Mastodon Social Network Server