CVE-2026-77641
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.
- Score
- CVSS 3.1 8.2 High
- Status
- Analyzed - cve@mitre.org
- Published
- 2026-08-20
- Last modified
- 2026-10-18
- Weaknesses
- CWE-252
Affected products
References
- https://gitlab.torproject.org/tpo/core/tor/-/raw/tor-0.4.9.9/ChangeLog
