Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.4.19 and from 4.5.0 until 4.5.12, Mastodon's app/models/concerns/user/ldap_authenticable.rb mutates OpenSSL::SSL::SSLContext::DEFAULT_PARAMS when LDAP authentication uses LDAP_TLS_NO_VERIFY=true, disabling SSL and TLS certificate verification globally for requests made by puma web processes while sidekiq background jobs remain unaffected. This issue is fixed in versions 4.4.19 and 4.5.12.

No CVSS v4.0

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation none

Automatable no

Technical Impact total

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
mastodon mastodon affected
Version Status Constraints
< 4.4.19 affected —
>= 4.5.0, < 4.5.12 affected —

No data.

No data.

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Project Subscriptions

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Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/mastodon/mastodon/commit/2ccb6ef277e725d1932295690cf8ab9d3dc03149 cve-icon cve-icon
https://github.com/mastodon/mastodon/commit/5748d0b16ea09001e0933f76c7afe814e09652ef cve-icon cve-icon
https://github.com/mastodon/mastodon/commit/761c61b42590a2fd91442fc15a0a7583e48bbea4 cve-icon cve-icon
https://github.com/mastodon/mastodon/pull/39571 cve-icon cve-icon
https://github.com/mastodon/mastodon/releases/tag/v4.4.19 cve-icon cve-icon
https://github.com/mastodon/mastodon/releases/tag/v4.5.12 cve-icon cve-icon
https://github.com/mastodon/mastodon/security/advisories/GHSA-3rhr-8phh-jm86 cve-icon cve-icon
History

Tue, 18 Aug 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Tue, 18 Aug 2026 15:15:00 +0000

Type Values Removed Values Added
Description Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.4.19 and from 4.5.0 until 4.5.12, Mastodon's app/models/concerns/user/ldap_authenticable.rb mutates OpenSSL::SSL::SSLContext::DEFAULT_PARAMS when LDAP authentication uses LDAP_TLS_NO_VERIFY=true, disabling SSL and TLS certificate verification globally for requests made by puma web processes while sidekiq background jobs remain unaffected. This issue is fixed in versions 4.4.19 and 4.5.12.
Title Mastodon: Unwanted deactivation of SSL/TLS certificate verification
Weaknesses CWE-295
References
Metrics cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-18T15:51:15.337Z

Reserved: 2026-07-07T15:00:50.978Z

Link: CVE-2026-59825

cve-icon Vulnrichment

Updated: 2026-08-18T15:51:12.220Z

cve-icon NVD

Status : Received

Published: 2026-08-18T15:16:55.623

Modified: 2026-08-18T16:18:11.260

Link: CVE-2026-59825

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-18T16:45:04Z

Weaknesses