CVE-2025-62176
Joinmastodon Mastodon ≤ 4.2.27
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:NSummary
CVE-2025-62176 is a medium-severity Improper Handling of Insufficient Permissions or Privileges (CWE-280) vulnerability in Joinmastodon Mastodon. Its CVSS base score is 4.3 (Medium).
Operationally, ranked at the 17th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-24 (Access Control Decisions) and AC-25 (Reference Monitor) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-34111
Vulnerability Data
Mastodon is a free, open-source social network server based on ActivityPub. In Mastodon before 4.4.6, 4.3.14, and 4.2.27, the streaming server accepts serving events for public timelines to clients using any valid authentication token, even if those tokens lack the…
more
read:statuses scope. This allows OAuth clients without the read scope to subscribe to public channels and receive public timeline events. The impact is limited, as this only affects new public posts published on the public timelines and requires an otherwise valid token, but this may lead to unexpected access to public posts in a limited-federation setting. This issue has been patched in versions 4.4.6, 4.3.14, and 4.2.27. No known workarounds exist.
- CWE(s)
Related Threats
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
—
—
- 6 hardening rules · 3 OS baselines
V6.2.2V8.3.3
Mitigating Controls (NIST 800-53 r5) AI
Ensuring access decisions are applied to every request structurally prevents the product from taking unexpected paths when privileges are lacking.
A reference monitor that is always invoked guarantees privilege checks occur, eliminating the root condition for improper insufficient-privilege handling.
Access enforcement directly stops code from proceeding on insufficient privileges by applying authorization checks before resource access.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Defining, enforcing and reviewing access permissions with least privilege directly prevents code paths that mishandle insufficient privileges.
Runtime monitoring of software and data surfaces adverse events triggered by unhandled permission failures.
Generating logs of permission-related events enables detection and analysis of improper handling.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing can detect missing or incorrect privilege handling.
Defines access-control policy that should prevent insufficient-privilege situations.
Specifies how access rights are granted, reviewed and revoked, directly addressing privilege handling.
Requires explicit management of privileged access rights, reducing the chance of missing privilege checks.
Secure-SDLC practices include privilege checks during design and coding.
Secure-coding standards require proper permission checks before resource access.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (2 rules)
- V-248548 OL 8 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-280
- V-248596 OL 8 must enable the SELinux targeted policy. prevents CWE-280
Oracle Linux 9 (1 rule)
- V-271452 OL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-280
RHEL 9 (2 rules)
- V-258078 RHEL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-280
- V-272496 RHEL 9 must elevate the SELinux context when an administrator calls the sudo command. prevents CWE-280