Spoofing Vulnerability in Mastodon Social Network Server
CVE-2026-46349

5.3MEDIUM

Key Information:

Vendor

Mastodon

Status
Mastodon
Vendor
CVE Published:
24 June 2026

What is CVE-2026-46349?

Mastodon, an open-source social network server, has a vulnerability in its processing of incoming activities signed with Linked-Data Signatures prior to specific versions. This flaw allows attackers to manipulate legitimate signed JSON-LD activities from third-party actors, leading to unauthorized processing. The issue has been addressed in versions 4.5.10, 4.4.17, and 4.3.23 to enhance security against these spoofing attacks.

Affected Version(s)

mastodon >= 4.5.0-beta.1, < 4.5.10

References

https://github.com/mastodon/mastodon/security/advisories/...
x_refsource_CONFIRM

CVSS V3.1

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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