Critical severity · published Aug 20, 2026
CVE-2026-77638
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…
9.0
CVSS
0.3%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 22% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
TO
Tor · torproject
0.3.5.3-alpha before 0.4.9.11 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-77638
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-77638
Permissions Required
https://gitlab.torproject.org/tpo/core/tor/-/raw/tor-0.4.9.11/ChangeLog
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