CVE-2026-77639
Published:August 20, 2026
Updated:September 24, 2026
Tor before 0.4.9.9 was prone to a compression bomb bypass where an attacker could concatenate many gzip or zlib sub-streams, each just under the per-stream detection threshold, to avoid the compression bomb check entirely. This is TROVE-2026-022.
Affected Packages
https://gitlab.torproject.org/tpo/core/tor.git (SCM_GIT):
Affected version(s) >=tor-0.0.2pre8 <tor-0.4.9.9Fix Suggestion:
Update to version tor-0.4.9.9Related Resources (1)
Do you need more information?
Contact UsCVSS v4
Base Score:
6.9
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
LOW
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Weakness Type (CWE)
Unprotected Alternate Channel
EPSS
Base Score:
0.23