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TI-2023-18301 Aliases CVE-2023-36460

Mastodon vulnerable to arbitrary file creation through media attachments

Priority HIGH 70CWE-22Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

Mastodon 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, attackers using carefully crafted media files can cause Mastodon's media processing code to create arbitrary files at any location. This allows attackers to create and overwrite any file Mastodon has access to, allowing Denial of Service and arbitrary Remote Code Execution. Versions 3.5.9, 4.0.5, and 4.1.3 contain a patch for this issue.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.4011 98th percentileScored 2026-11-07
Fix Fixed mastodon (mastodon): 3.5.9, 4.0.5, 4.1.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
mastodonmastodon3.5.0 to before 3.5.9; 4.0.0 to before 4.0.5; 4.1.0 to before 4.1.33.5.9, 4.0.5, 4.1.3Patch availableCNA
  • mastodon Vendormastodon Affected 3.5.0 to before 3.5.9; 4.0.0 to before 4.0.5; 4.1.0 to before 4.1.3 Fixed in 3.5.9, 4.0.5, 4.1.3 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*3.5.0 to before 3.5.9; 4.0.0 to before 4.0.5; 4.1.0 to before 4.1.3Vulnerablemastodon
  • cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:* Versions 3.5.0 to before 3.5.9; 4.0.0 to before 4.0.5; 4.1.0 to before 4.1.3 Vulnerable ·mastodon

Remediation

  • Fix · CNA mastodon (mastodon) Fixed in 3.5.9, 4.0.5, 4.1.3

Timeline

  1. 2026-10-02 Threatist record created from CVE-2023-36460

References

Patch 1

Advisory 4

Other 1

  • TI-2022-02004 Improper Restriction of Excessive Authentication Attempts in mastodon/mastodon CVSS 3.1CRITICAL 9.8
  • TI-2025-34613 Mastodon e‑mail throttle misconfiguration allows unlimited email confirmations against unconfirmed emails CVSS 3.1HIGH 7.5
  • TI-2022-22936 Mastodon through 4.0.2 allows attackers to cause a denial of service (large Sidekiq pull… CVSS 3.1HIGH 7.5
  • TI-2023-13359 Mastodon's blind LDAP injection in login allows the attacker to leak arbitrary attributes from LDAP database CVSS 3.1HIGH 7.7
  • TI-2024-16846 External OpenID Connect Account Takeover by E-Mail Change in mastodon CVSS 3.1HIGH 7.4
  • TI-2024-15826 Mastodon Remote user impersonation and takeover CVSS 3.1CRITICAL 9.8
See all 41 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences