CVE-2026-77641

Published Aug 20, 2026

Last updated 4 days ago

Overview

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.
Source
cve@mitre.org
NVD status
Received

Risk scores

CVSS 3.1

Type
Secondary
Base score
6.5
Impact score
4.2
Exploitability score
2.2
Vector string
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
Severity
MEDIUM

Weaknesses

cve@mitre.org
CWE-252

Social media

Hype score
Not currently trending

References

Sources include official advisories and independent security research.