The daemon in Tor through 0.4.1.8 and 0.4.2.x through 0.4.2.6 does not verify that a…
Priority LOW 29Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA.
Summary
The daemon in Tor through 0.4.1.8 and 0.4.2.x through 0.4.2.6 does not verify that a rendezvous node is known before attempting to connect to it, which might make it easier for remote attackers to discover circuit information. NOTE: The network team of Tor claims this is an intended behavior and not a vulnerability
Why it matters now
EPSS 0.02499 84th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged 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 · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:* | up to 0.4.1.8; 0.4.2.0 – 0.4.2.6 | Vulnerable | torproject |
- cpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:* Versions up to 0.4.1.8; 0.4.2.0 – 0.4.2.6 Vulnerable ·torproject
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2020-8516
- 2026-10-03 Alias added: GHSA-gvvc-pv9r-rg5q
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-2020-8516 · CVE Program
- CVE-2020-8516 · NVD
- FIRST EPSS
- GHSA-gvvc-pv9r-rg5q · GitHub Advisory Database · CC BY 4.0
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