Vulnerability in Hotwired Turbo

CVE-2025-66803

Race condition in the turbo-frame element handler in Hotwired Turbo before 8.0.x causes logout operations to fail when delayed frame responses reapply session cookies after logout. This can be exploited by remote attackers via selective network delays (e.g. delaying requests based on sequence or timing) or by physically proximate attackers when the race condition occurs naturally on shared computers.

Vulnerability class: Race Condition

EPSS: 0.002 (15.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-66803?
CVE-2025-66803 is a medium-severity vulnerability in Hotwired Turbo, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 4.8/10. Published 2026-01-20.
How severe is CVE-2025-66803?
Medium severity. CVSS v3 base score is 4.8 out of 10.