Cyber Resilience

CVE-2025-62175

Joinmastodon Mastodon ≤ 4.2.27

Published
13 October 2025
Modified
20 October 2025
Patch / advisory
CVSS Score v3.1 4.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
EPSS Score 0.0021 12th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2025-62175 is a medium-severity Improper Check for Dropped Privileges (CWE-273) vulnerability in Joinmastodon Mastodon. Its CVSS base score is 4.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 12th 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

Vulnerability Data

Mastodon is a free, open-source social network server based on ActivityPub. In versions before 4.4.6, 4.3.14, and 4.2.27, disabling or suspending a user account does not disconnect the account from the streaming API. This allows disabled or suspended accounts to…

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continue receiving real-time updates through existing streaming connections and to establish new streaming connections, even though they cannot interact with other API endpoints. This undermines moderation actions, as administrators expect disabled or suspended accounts to be fully disconnected from the service. 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

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1134 Access Token Manipulation Stealth
Adversaries may modify access tokens to operate under a different user or system security context to perform actions and bypass access controls.
T1548 Abuse Elevation Control Mechanism Privilege Escalation
Adversaries may circumvent mechanisms designed to control privilege elevation to gain higher-level permissions.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-37903Same product: Joinmastodon Mastodon
CVE-2026-27468Same product: Joinmastodon Mastodon
CVE-2026-23964Same product: Joinmastodon Mastodon
CVE-2026-23961Same product: Joinmastodon Mastodon
CVE-2026-33869Same product: Joinmastodon Mastodon
CVE-2024-25618Same product: Joinmastodon Mastodon
CVE-2023-36462Same product: Joinmastodon Mastodon
CVE-2024-25619Same product: Joinmastodon Mastodon
CVE-2024-23832Same product: Joinmastodon Mastodon
CVE-2025-27399Same product: Joinmastodon Mastodon

Affected Assets

joinmastodon
mastodon
≤ 4.2.27 · 4.3.0 — 4.3.14 · 4.4.0 — 4.4.6

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

Always-invoked reference monitor guarantees privilege checks occur and cannot be bypassed or mishandled.

Enforces approved authorizations so insufficient privileges produce a proper denial instead of mishandled failure.

Requires every access request to be decided against current authorizations, preventing ad-hoc privilege handling.

Employing least privilege requires that privilege-dropping operations succeed and are verified before continuing.

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.

PR.AA-05 mostly match
prevents

Enforcing least-privilege access policies directly prevents improper handling of insufficient privileges.

PR.PS-06 mostly match
prevents

Secure SDLC activities (code review, static analysis, testing) catch missing or incorrect privilege-drop checks, but eliminating only this one flaw covers only a fraction of the control's broader intent.

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.

prevents

Privileged-access-rights control directly limits the situations in which insufficient privileges can occur.

finds

Security testing can detect failed privilege drops, yet the control does not require such checks as part of its core intent.

prevents

Information-access-restriction mechanisms enforce least-privilege checks that mitigate the weakness at runtime.

prevents

Access control policy defines privilege boundaries but does not guarantee correct runtime handling when privileges prove insufficient.

prevents

Access-rights provisioning and review reduce privilege gaps, yet do not address the software’s failure to handle insufficient privileges gracefully.

degrades

Control of privileged utility programs includes ensuring privilege-dropping operations are verified before use.

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 9 (2 rules)
  • V-271452 OL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-274
  • V-271640 OL 9 must be configured so that the Network File System (NFS) is configured to use RPCSEC_GSS. prevents CWE-274
RHEL 9 (1 rule)
  • V-258078 RHEL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-274

References