TI-2023-22616 Aliases CVE-2023-42451

Mastodon Invalid Domain Name Normalization vulnerability

LOW 34CWE-706Published 2023-09-19 · Updated 2024-09-24

Key facts

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

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

Summary

Mastodon is a free, open-source social network server based on ActivityPub. Prior to versions 3.5.14, 4.0.10, 4.1.8, and 4.2.0-rc2, under certain circumstances, attackers can exploit a flaw in domain name normalization to spoof domains they do not own. Versions 3.5.14, 4.0.10, 4.1.8, and 4.2.0-rc2 contain a patch for this issue.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00667 52nd percentileScored 2026-11-07

Fix Fixed mastodon (mastodon): 3.5.14, 4.0.10, 4.1.8 +1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

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

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
mastodon	mastodon	before 3.5.14; 4.0.0 to before 4.0.10; 4.1.0 to before 4.1.8; 4.2.0-beta1 to before 4.2.0-rc2	3.5.14, 4.0.10, 4.1.8, 4.2.0-rc2	Patch available	CNA

mastodon Vendormastodon Affected before 3.5.14; 4.0.0 to before 4.0.10; 4.1.0 to before 4.1.8; 4.2.0-beta1 to before 4.2.0-rc2 Fixed in 3.5.14, 4.0.10, 4.1.8, 4.2.0-rc2 Patch available CNA

CPE configurations NVD · 5

CPE	Versions	Role	Vendor
cpe:2.3:a:joinmastodon:mastodon::::::::	before 3.5.14; 4.0.0 to before 4.0.10; 4.1.0 to before 4.1.8	Vulnerable	mastodon
cpe:2.3:a:joinmastodon:mastodon:4.2.0:beta1::::::	4.2.0 beta1	Vulnerable	mastodon
cpe:2.3:a:joinmastodon:mastodon:4.2.0:beta2::::::	4.2.0 beta2	Vulnerable	mastodon
cpe:2.3:a:joinmastodon:mastodon:4.2.0:beta3::::::	4.2.0 beta3	Vulnerable	mastodon
cpe:2.3:a:joinmastodon:mastodon:4.2.0:rc1::::::	4.2.0 rc1	Vulnerable	mastodon

cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:* Versions before 3.5.14; 4.0.0 to before 4.0.10; 4.1.0 to before 4.1.8 Vulnerable ·mastodon
cpe:2.3:a:joinmastodon:mastodon:4.2.0:beta1:*:*:*:*:*:* Versions 4.2.0 beta1 Vulnerable ·mastodon
cpe:2.3:a:joinmastodon:mastodon:4.2.0:beta2:*:*:*:*:*:* Versions 4.2.0 beta2 Vulnerable ·mastodon
cpe:2.3:a:joinmastodon:mastodon:4.2.0:beta3:*:*:*:*:*:* Versions 4.2.0 beta3 Vulnerable ·mastodon
cpe:2.3:a:joinmastodon:mastodon:4.2.0:rc1:*:*:*:*:*:* Versions 4.2.0 rc1 Vulnerable ·mastodon

Remediation

Fix · CNA mastodon (mastodon) Fixed in 3.5.14, 4.0.10, 4.1.8, 4.2.0-rc2

Timeline

2026-10-02 Threatist record created from CVE-2023-42451

References

Patch 1

https://github.com/mastodon/mastodon/commit/eeab3560fc0516070b3fb97e089b15ecab1938c8

Advisory 1

https://github.com/mastodon/mastodon/security/advisories/GHSA-v3xf-c9qf-j667

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-2023-18301 Mastodon vulnerable to arbitrary file creation through media attachments CVSS 3.1CRITICAL 10.0
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

See all 41 →

Sources

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