Use after free in Tor
Priority MEDIUM 48CWE-416Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.0 · NVD. Fix status from CNA. Impact type from CWE-416 and the CVSS impact.
Summary
A use-after-free issue was discovered in Tor 0.3.2.x before 0.3.2.10. It allows remote attackers to cause a denial of service (relay crash) because the KIST implementation allows a channel to be added more than once in the pending list.
Why it matters now
EPSS 0.1479 96th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by the CNA and 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 |
|---|---|---|---|---|---|
| — | Tor | Tor | — | No fix listed | CNA |
- Tor Vendor— Affected Tor Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:* | 0.3.2.0 to before 0.3.2.10 | Vulnerable | torproject |
- cpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:* Versions 0.3.2.0 to before 0.3.2.10 Vulnerable ·torproject
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2018-0491
- 2026-10-03 Alias added: GHSA-8wr4-7fjq-4qxw
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-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
- TI-2019-06464 In Tor before 0.3.3.12, 0.3.4.x before 0.3.4.11, 0.3.5.x before 0.3.5.8, and 0.4.x before… CVSS 3.0HIGH 7.5
Sources
- CVE-2018-0491 · CVE Program
- CVE-2018-0491 · NVD
- FIRST EPSS
- GHSA-8wr4-7fjq-4qxw · GitHub Advisory Database · CC BY 4.0
- CVE-2018-0491 · 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