CVEvulnerability
CVE-2026-77641
8.2 HIGH
Official page ↗
- Status
- Analyzed
- Published
- 2026-08-20
- Last modified
- 2026-10-18
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 6.5 MEDIUM — CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
- CVSS 3.1 ([email protected])
- 8.2 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
- Weaknesses
- CWE-252
Description
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.
Affected configurations
• torproject tor (< 0.4.9.9)
Related
Weakness · CWE (1)
- CWE-252 Unchecked Return Value weakness
References
- https://gitlab.torproject.org/tpo/core/tor/-/raw/tor-0.4.9.9/ChangeLog Release Notes, Vendor Advisory