CVE-2026-77641tor before 0.4.9.9 was prone to a NULL write after free when sending a CONFLUX_SWITCH cell fails.
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 6.5 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
- Weakness (CWE)
- CWE-252
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- mitre
- NVD analysis
- Analyzed
- Record last updated
- Aug 27, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
torproject Tor torproject:tor (from the name) | from 0.4.8.1-alpha before 0.4.9.9 | CNA record |
torproject tor torproject:tor | before 0.4.9.9 | NVD |
References
- https://gitlab.torproject.org/tpo/core/tor/-/raw/tor-0.4.9.9/ChangeLogrelease-notes, vendor-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.