CVE-2025-68621 Trilium Notes has a Timing Attack Vulnerability in /api/login/sync

High 7.4 Published 6 Feb 2026 Updated 9 Feb 2026

Attackers can bypass authentication via timing attacks on the sync endpoint, gaining full read/write access to the victim's knowledge base.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2025-68621?

CVE-2025-68621 is a high-severity authentication bypass vulnerability in TriliumNext Trilium, published on 6 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Trilium Notes is an open-source, cross-platform hierarchical note taking application with focus on building large personal knowledge bases. Prior to 0.101.0, a critical timing attack vulnerability in Trilium's sync authentication endpoint allows unauthenticated remote attackers to recover HMAC authentication hashes byte-by-byte through statistical timing analysis. This enables complete authentication bypass without password knowledge, granting full read/write access to victim's knowledge base. This vulnerability is fixed in 0.101.0.

Weakness: CWE-208

Which versions are affected by CVE-2025-68621?

It affects 1 product.

Products include Triliumnotes Trilium.

How do I fix CVE-2025-68621?

No fix has been published for CVE-2025-68621 yet. Limit exposure of the affected software until one is available.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2025-68621 being exploited?

There is no known exploitation of CVE-2025-68621 in the wild and no public exploit code.

Public exploit code: 1 proofs of concept on GitHub.

Sources

Also known as GHSA-hxf6-58cx-qq3x.