This page tracks the Debian fix status. The vulnerability itself is described on the main CVE page.
View CVE-2026-77641 →
DEBIAN-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() w...
Original description
The description as published by the source.
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: OSV.dev (Open Source Vulnerabilities) OSV
Affected packages
Debian:12
tor
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.4.9.9-1"}]}]
Debian:13
tor
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.4.9.11-0+deb13u1"}]}]
Debian:14
tor
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.4.9.9-1"}]}]
References
- advisory security-tracker.debian.org