PT-2026-79151 · Torproject+3 · Tor
CVE-2026-77641
·
Published
2026-08-20
·
Updated
2026-08-20
CVSS v3.1
8.2
High
| Vector | AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H |
Name of the Vulnerable Software and Affected Versions
tor versions prior to 0.4.9.9
Description
A NULL write after free occurs when sending a CONFLUX SWITCH cell fails. The system ignores the return value of the
relay send command from edge() function. Consequently, a send failure triggers circuit mark for close() and removes the leg via cfx del leg(), which goes undetected. This leads the caller to write to the freed current leg, resulting in a crash.Recommendations
Update tor to version 0.4.9.9 or later.
Exploit
Fix
Unchecked Return Value
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Weakness Enumeration
Related Identifiers
Affected Products
Tor