SEPTEMBER 15, 2026
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Case File

CVE-2026-77641

MEDIUM · CVSS 6.5 EPSS 0.20%

Source: NVD + CISA KEV + EPSS · Published 2026-08-20 · Last synced 2026-09-15

CyberRota Analysis

AI-Generated

Tor versions prior to 0.4.9.9 are susceptible to a NULL write after free vulnerability that occurs when sending a CONFLUX_SWITCH cell fails, leading to potential crashes. The failure to handle the return value from relay_send_command_from_edge() allows for undetected send failures, which can compromise the stability of the application. Organizations utilizing Tor should prioritize this issue to mitigate potential disruptions in service.

CVE
CVE-2026-77641
Severity
MEDIUM
CVSS
6.5
EPSS
0.20%

Original NVD 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.

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