Tor Browser through 10.5.6 and 11.x through 11.0a4 allows a correlation attack that can…
Priority LOW 28CWE-532Published · Updated
Key facts
- Attack vector
- Physical
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-532.
Summary
Tor Browser through 10.5.6 and 11.x through 11.0a4 allows a correlation attack that can compromise the privacy of visits to v2 onion addresses. Exact timestamps of these onion-service visits are logged locally, and an attacker might be able to compare them to timestamp data collected by the destination server (or collected by a rogue site within the Tor network).
Why it matters now
EPSS 0.00475 41st percentileScored 2026-11-07
Public exploit Yes 2 exploit referencesTagged by NVD
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:torproject:tor_browser:*:*:*:*:*:*:*:* | up to 10.5.6 | Vulnerable | torproject |
| cpe:2.3:a:torproject:tor_browser:11.0:alpha2:*:*:*:*:*:* | 11.0 alpha2 | Vulnerable | torproject |
| cpe:2.3:a:torproject:tor_browser:11.0:alpha4:*:*:*:*:*:* | 11.0 alpha4 | Vulnerable | torproject |
| cpe:2.3:o:apple:macos:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Apple |
| cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Linux |
| cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Microsoft |
- cpe:2.3:a:torproject:tor_browser:*:*:*:*:*:*:*:* Versions up to 10.5.6 Vulnerable ·torproject
- cpe:2.3:a:torproject:tor_browser:11.0:alpha2:*:*:*:*:*:* Versions 11.0 alpha2 Vulnerable ·torproject
- cpe:2.3:a:torproject:tor_browser:11.0:alpha4:*:*:*:*:*:* Versions 11.0 alpha4 Vulnerable ·torproject
- cpe:2.3:o:apple:macos:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Apple
- cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Linux
- cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Microsoft
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2021-39246
- 2026-10-03 Alias added: GHSA-mqmf-5457-4f39
References
Exploit 2
More torproject Tor Browser vulnerabilities
- TI-2018-12134 NoScript Classic before 5.1.8.7, as used in Tor Browser 7.x and other products, allows… CVSS 3.0CRITICAL 9.8
- TI-2019-09791 Tor Browser through 8.5.3 has an information exposure vulnerability. CVSS 3.0MEDIUM 5.3
- TI-2017-12239 Tor Browser on Windows before 8.0 allows remote attackers to bypass the intended… CVSS 3.0MEDIUM 4.3
- TI-2019-09231 Tor Browser before 8.0.1 has an information exposure vulnerability. CVSS 3.1MEDIUM 4.3
Sources
- CVE-2021-39246 · CVE Program
- CVE-2021-39246 · NVD
- FIRST EPSS
- GHSA-mqmf-5457-4f39 · GitHub Advisory Database · CC BY 4.0
- CVE-2021-39246 · 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