ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2025-54879

Mastodon is a free, open-source social network server based on ActivityPub Mastodon which facilitates LDAP configuration for authentication.

Published Aug 5, 2025 · catalog updated Aug 6, 2025 · Mastodon is a free,

Last checked Oct 23, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2025-54879. EPSS is 0.56%. Act only if a listed version of Mastodon is a free, is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Mastodon is a free,).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Medium5.3
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.56%
Remediation
Version ranges on file
Affected products
vendor mastodon mastodon 4.3.0, < 4.3.11

Mastodon is a free, open-source social network server based on ActivityPub Mastodon which facilitates LDAP configuration for authentication. In versions 3.1.5 through 4.2.24, 4.3.0 through 4.3.11 and 4.4.0 through 4.4.3, Mastodon's rate-limiting system has a critical configuration error where the email-based throttle for confirmation emails incorrectly checks the password reset path instead of the confirmation path, effectively disabling per-email limits for confirmation requests. This allows attackers to bypass rate limits by rotating IP addresses and send unlimited confirmation emails to any

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor mastodon mastodon 4.3.0, < 4.3.114.3.0, < 4.3.11

How to fix CVE-2025-54879

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2025-54879. EPSS is 0.56%. Act only if a listed version of Mastodon is a free, is installed.

Which versions are affected?

Compare what you have installed with mastodon mastodon 4.3.0, < 4.3.11 4.3.0, < 4.3.11. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.56%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Aug 5, 2025 · EUVD

    Detected

    Mastodon is a free, open-source social network server based on ActivityPub Mastodon which facilitates LDAP configuration for authentication. In versions 3.1.5 through 4.2.24, 4.3.0 through 4.3.11 and 4.4.0 through 4.4.3, Mastodon's rate-limiting system has a critical configuration error where the email-based throttle for confirmation emails incorrectly checks the password reset path instead of the

  2. Aug 6, 2025 · EUVD

    Updated

    Mastodon is a free, open-source social network server based on ActivityPub Mastodon which facilitates LDAP configuration for authentication. In versions 3.1.5 through 4.2.24, 4.3.0 through 4.3.11 and 4.4.0 through 4.4.3, Mastodon's rate-limiting system has a critical configuration error where the email-based throttle for confirmation emails incorrectly checks the password reset path instead of the

Sources

  • CVE.orgVulnerability recordCVE-2025-54879

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2025-54879

    30-day exploitation probability 0.56%

    first.org
  • EUVDVulnerability recordEUVD-2025-23661

    Mastodon is a free, open-source social network server based on ActivityPub Mastodon which facilitates LDAP configuration for authentication. In versions 3.1.5 through 4.2.24, 4.3.0 through 4.3.11 and 4.4.0 through 4.4.3, Mastodon's rate-limiting system has a critical configuratio

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Oct 23, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSOct 23, 2026
  • CVE.orgOct 21, 2026
  • EUVDOct 20, 2026
CVE-2025-54879: Mastodon is a free, open-source social network serv… · ZeroDay Findings