CVE-2026-59825
High
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.
SeverityHigh
CVSS7.4
Exploit probability—
Product
Mastodon
PublishedAug 18, 2026
First seenAug 18, 2026
Weakness typeCWE-295CWE-295
How to fix
Sources list no fixed version or patch link for this vulnerability.
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| mastodon mastodon | < 4.4.19, >= 4.5.0, < 4.5.12 | — |
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