MEDIUMVulnerability

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.

Properties

severity
MEDIUM
score
6.5
epss_score
0.00194
cve_id
CVE-2026-77641
vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
published_at
2026-08-20T21:17:11.517
last_modified
2026-09-03T17:24:13.970
epss_percentile
0.09133

Related Entities (3)

ENRICHED_BY (1)

[Source]FIRST EPSS

HAS_WEAKNESS (1)

[Weakness]Unchecked Return Value

DESCRIBED_BY (1)

[Source]NVD

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