Account takeover via exposed JWT signing secret
Published Sep 1, 2026 · Updated Sep 2, 2026
Privilege escalation in fast-note-sync-service 2.13.7 and earlier allows remote attackers to impersonate users through a forged JWT. An incorrect check treats admin-uid 0 as authorizing any authenticated account, exposing authTokenKey through the admin configuration endpoint. Exploitation requires enabled self-registration and an empty, known, or predictable machine_id in a Docker deployment, permitting access to and alteration or deletion of synced notes.
Summary
What happened
Privilege escalation in fast-note-sync-service 2.13.7 and earlier allows remote attackers to impersonate users through a forged JWT. An incorrect check treats admin-uid 0 as authorizing any authenticated account, exposing authTokenKey through the admin configuration endpoint. Exploitation requires enabled self-registration and an empty, known, or predictable machine_id in a Docker deployment, permitting access to and alteration or deletion of synced notes.
The record
- CVE
- CVE-2026-52111
- Published
- Sep 1, 2026
- Updated
- Sep 2, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-284, T1550.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 1, 2026CVE publishedPublication date reported by the CVE source.
- Sep 2, 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?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
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
- Fast Note Sync Service account-impersonation chainproof of concept · demonstrated
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