CVE-2026-77641
CVSS Score
6.5
EPSS Score
0.0%
EPSS Percentile
0th
tor before 0.4.9.9 was prone to a NULL write after free when sending a CONFLUX_SWITCH cell fails. The return value of relay_send_command_from_edge() was ignored, so a send failure (which calls circuit_mark_for_close() and removes the leg via cfx_del_leg()) would go undetected, causing the caller to write to the now-freed current leg and resulting in a crash. This is TROVE-2026-017.
| CWE | CWE-252 |
| Vendor | torproject |
| Product | tor |
| Published | Aug 20, 2026 |
Stay Ahead of the Next One
Get instant alerts for torproject tor
Be the first to know when new medium vulnerabilities affecting torproject tor are published — delivered to Slack, Telegram or Discord.
Get Free Alerts →
Free · No credit card · 60 sec setup
CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
High
Affected Versions
torproject / Tor
0.4.8.1-alpha < 0.4.9.9