Private status enumeration via inconsistent error handling
Published Dec 9, 2025 · Updated Jan 8, 2026
Observable response discrepancy in Mastodon allows remote attackers to confirm that a known private status exists through an unauthenticated request. The fetchStatus failure path and statuses reducer handle 404 responses for already-known statuses inconsistently, and a non-English Accept-Language request exposes the difference. The attacker must know an inaccessible status identifier; the oracle reveals only existence, not content or any other status property.
Summary
What happened
Observable response discrepancy in Mastodon allows remote attackers to confirm that a known private status exists through an unauthenticated request. The fetchStatus failure path and statuses reducer handle 404 responses for already-known statuses inconsistently, and a non-English Accept-Language request exposes the difference. The attacker must know an inaccessible status identifier; the oracle reveals only existence, not content or any other status property.
The record
- CVE
- CVE-2025-67500
- Published
- Dec 9, 2025
- Updated
- Jan 8, 2026
- Vendor
- Mastodon
- Product
- Mastodon
- Classifications
- CWE-204, T1595
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 9, 2025CVE publishedPublication date reported by the CVE source.
- Jan 8, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 4.2.28
- Affected versionversion=>= 4.3.0-beta.1, < 4.3.15
- Affected versionversion=>= 4.4.0-beta.1, < 4.4.10
- Affected versionversion=>= 4.5.0-beta.1, < 4.5.3
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo