CVE-2026-59825
Mastodon: Unwanted deactivation of SSL/TLS certificate verification
- State
- Published
- Severity
- 7.4 High
- Published
- Aug 18, 2026
- Updated
- Aug 18, 2026
- Reserved
- Jul 7, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.4 High | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N | GitHub_M |
Weaknesses
- CWE-295 Improper Certificate Validation
Affected Products
| Product | Versions |
|---|---|
mastodonmastodon |
|
References
- https://github.com/mastodon/mastodon/security/advisories/GHSA-3rhr-8phh-jm86
- https://github.com/mastodon/mastodon/pull/39571
- https://github.com/mastodon/mastodon/commit/2ccb6ef277e725d1932295690cf8ab9d3dc03149
- https://github.com/mastodon/mastodon/commit/5748d0b16ea09001e0933f76c7afe814e09652ef
- https://github.com/mastodon/mastodon/commit/761c61b42590a2fd91442fc15a0a7583e48bbea4
- https://github.com/mastodon/mastodon/releases/tag/v4.4.19
- https://github.com/mastodon/mastodon/releases/tag/v4.5.12
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