CVE Tools
Sign in

CVE-2026-59825

Mastodon: Unwanted deactivation of SSL/TLS certificate verification

Published: Aug 18, 2026Updated: Aug 18, 2026 Sources: CVE List NVDCWE-295
7.4HIGH
NVD MITRE
EPSS Score
0.3%
Top 72.6%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available
Self-Check
Not available

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:HPR:NUI:NS:UC:HI:HA:N
Exploitability
AV:NAttack Vector
Network
AC:HAttack Complexity
High
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:NAvailability
None
Open in CVSS calculator →

Weaknesses

CWE-295

Affected Products

mastodon
oss-projectaka mastodon/mastodon
mastodonOn-prem
Communications / messaging-chat

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.
Is your org exposed to CVE-2026-59825?We can run the check for you — a free external exposure review, no install. Check my exposure

Attack Graph

Products CVE Techniques Tactics

Click technique nodes for MITRE ATT&CK details · drag to pan · Ctrl/⌘ + scroll to zoom, or go fullscreen.

MITRE ATT&CK

1 technique
Collection
View detailed technique mapping

References

https://github.com/mastodon/mastodon/security/advisories/GHSA-3rhr-8phh-jm86
github.com
https://github.com/mastodon/mastodon/pull/39571
github.com
https://github.com/mastodon/mastodon/commit/2ccb6ef277e725d1932295690cf8ab9d3dc03149
github.com
and 4 more references View all →

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2026-59825 and every CVE in our database. Create a free account — no credit card required.

Create Free Account
Plain-language analysis
Impact assessment and exploitation scenario in plain English
Attack graph visualization
Interactive attack path and kill chain mapping
Exploit details & PoC links
ExploitDB, Metasploit, GitHub PoCs with direct links
Nuclei scanner templates
Ready-to-use vulnerability scanner templates
Full remediation guide
Patch instructions, workarounds, and compliance impact
Interactive AI chat
Ask questions about this vulnerability in natural language
Related vulnerabilities
Semantically similar CVEs and attack patterns
REST API & MCP access
Integrate vulnerability data into your workflows