CVE-2026-77638

HIGH CVSS 3.1: 8.9 EPSS 0.17%
Updated Sep 03, 2026
Torproject
Parameter Value
CVSS 8.9 (HIGH)
Affected Versions 0.3.5.3-alpha — 0.4.9.11
Fixed In 0.4.9.11
Type CWE-362 (Race Condition)
Vendor Torproject
Public PoC No

Tor before 0.4.9.11 is prone to a race condition where in just the right circumstances a rendezvous point could man-in-the-middle (impersonate) the onion service that the client was trying to reach.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
High
Difficult to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
Low
Partial disruption

CVSS Vector v3.1

Weakness Type (CWE)

Vulnerable Products 1

Configuration From (including) Up to (excluding)
Torproject Tor
cpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:*
0.3.5.3-alpha 0.4.9.11