Tor before 0.4.9.10 did not reject a CONFLUX_LINK cell that arrives on a circuit which…
Priority LOW 35CWE-821Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA.
Summary
Tor before 0.4.9.10 did not reject a CONFLUX_LINK cell that arrives on a circuit which already has attached streams. A malicious client could send a RELAY_COMMAND_BEGIN before the CONFLUX_LINK on the same circuit, attaching an exit stream that would later end up orphan leaving a dangling circuit back-pointer and a use-after-free (UAF) when the circuit is freed. This is TROVE-2026-025.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0025 16th percentileScored 2026-11-07
Fix Fixed Tor (torproject): 0.4.9.10
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| torproject | Tor | 0.4.8.1-alpha to before 0.4.9.10 | 0.4.9.10 | Patch available | CNA |
- Tor Vendortorproject Affected 0.4.8.1-alpha to before 0.4.9.10 Fixed in 0.4.9.10 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:* | before 0.4.9.10 | Vulnerable | torproject |
- cpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:* Versions before 0.4.9.10 Vulnerable ·torproject
Remediation
- Fix · CNA Tor (torproject) Fixed in 0.4.9.10
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2026-77584
- 2026-10-03 Alias added: GHSA-j5c4-cwjr-6vv5
References
More torproject Tor vulnerabilities
- TI-2016-07433 Use after free in Mozilla Firefox KEVCVSS 3.1HIGH 7.5
- TI-2023-09419 The SafeSocks option in Tor before 0.4.7.13 has a logic error in which the unsafe SOCKS4… CVSS 3.1MEDIUM 6.5
- TI-2018-00448 Use after free in Tor CVSS 3.0HIGH 7.5
- TI-2026-54108 Race condition in torproject Tor CVSS 3.1CRITICAL 9.0
- TI-2026-54112 Out-of-bounds write in torproject Tor CVSS 3.1CRITICAL 9.3
- TI-2026-32508 Tor before 0.4.9.7 has an out-of-bounds read when an END, a TRUNCATE, or a TRUNCATED cell… CVSS 3.1CRITICAL 9.1
Sources
- CVE-2026-77584 · CVE Program
- CVE-2026-77584 · NVD
- FIRST EPSS
- GHSA-j5c4-cwjr-6vv5 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-77584 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences