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TI-2019-06464 Aliases CVE-2019-8955GHSA-h3x5-p32h-w7q2

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…

Priority MEDIUM 40CWE-770Published · 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-770.

Summary

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 0.4.0.2-alpha, remote denial of service against Tor clients and relays can occur via memory exhaustion in the KIST cell scheduler.

Why it matters now

EPSS 0.04572 91st percentileScored 2026-11-07
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

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 18

CPEVersionsRoleVendor
cpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:*before 0.3.3.12; 0.3.4.8 to before 0.3.4.11Vulnerabletorproject
cpe:2.3:a:torproject:tor:0.3.4.0:alpha-dev:*:*:*:*:*:*0.3.4.0 alpha-devVulnerabletorproject
cpe:2.3:a:torproject:tor:0.3.4.1:alpha:*:*:*:*:*:*0.3.4.1 alphaVulnerabletorproject
cpe:2.3:a:torproject:tor:0.3.4.2:alpha:*:*:*:*:*:*0.3.4.2 alphaVulnerabletorproject
cpe:2.3:a:torproject:tor:0.3.4.3:alpha:*:*:*:*:*:*0.3.4.3 alphaVulnerabletorproject
cpe:2.3:a:torproject:tor:0.3.4.4:rc:*:*:*:*:*:*0.3.4.4 rcVulnerabletorproject
cpe:2.3:a:torproject:tor:0.3.4.5:rc:*:*:*:*:*:*0.3.4.5 rcVulnerabletorproject
cpe:2.3:a:torproject:tor:0.3.4.6:rc:*:*:*:*:*:*0.3.4.6 rcVulnerabletorproject
cpe:2.3:a:torproject:tor:0.3.4.7:rc:*:*:*:*:*:*0.3.4.7 rcVulnerabletorproject
cpe:2.3:a:torproject:tor:0.3.5.0:alpha-dev:*:*:*:*:*:*0.3.5.0 alpha-devVulnerabletorproject
  • cpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:* Versions before 0.3.3.12; 0.3.4.8 to before 0.3.4.11 Vulnerable ·torproject
  • cpe:2.3:a:torproject:tor:0.3.4.0:alpha-dev:*:*:*:*:*:* Versions 0.3.4.0 alpha-dev Vulnerable ·torproject
  • cpe:2.3:a:torproject:tor:0.3.4.1:alpha:*:*:*:*:*:* Versions 0.3.4.1 alpha Vulnerable ·torproject
  • cpe:2.3:a:torproject:tor:0.3.4.2:alpha:*:*:*:*:*:* Versions 0.3.4.2 alpha Vulnerable ·torproject
  • cpe:2.3:a:torproject:tor:0.3.4.3:alpha:*:*:*:*:*:* Versions 0.3.4.3 alpha Vulnerable ·torproject
  • cpe:2.3:a:torproject:tor:0.3.4.4:rc:*:*:*:*:*:* Versions 0.3.4.4 rc Vulnerable ·torproject
  • cpe:2.3:a:torproject:tor:0.3.4.5:rc:*:*:*:*:*:* Versions 0.3.4.5 rc Vulnerable ·torproject
  • cpe:2.3:a:torproject:tor:0.3.4.6:rc:*:*:*:*:*:* Versions 0.3.4.6 rc Vulnerable ·torproject
  • cpe:2.3:a:torproject:tor:0.3.4.7:rc:*:*:*:*:*:* Versions 0.3.4.7 rc Vulnerable ·torproject
  • cpe:2.3:a:torproject:tor:0.3.5.0:alpha-dev:*:*:*:*:*:* Versions 0.3.5.0 alpha-dev Vulnerable ·torproject
Show 8 more CPE
CPEVersionsRoleVendor
cpe:2.3:a:torproject:tor:0.3.5.1:alpha:*:*:*:*:*:*0.3.5.1 alphaVulnerabletorproject
cpe:2.3:a:torproject:tor:0.3.5.2:alpha:*:*:*:*:*:*0.3.5.2 alphaVulnerabletorproject
cpe:2.3:a:torproject:tor:0.3.5.3:alpha:*:*:*:*:*:*0.3.5.3 alphaVulnerabletorproject
cpe:2.3:a:torproject:tor:0.3.5.4:alpha:*:*:*:*:*:*0.3.5.4 alphaVulnerabletorproject
cpe:2.3:a:torproject:tor:0.3.5.5:alpha:*:*:*:*:*:*0.3.5.5 alphaVulnerabletorproject
cpe:2.3:a:torproject:tor:0.3.5.6:rc:*:*:*:*:*:*0.3.5.6 rcVulnerabletorproject
cpe:2.3:a:torproject:tor:0.3.5.7:*:*:*:*:*:*:*0.3.5.7Vulnerabletorproject
cpe:2.3:a:torproject:tor:0.4.0.1:alpha:*:*:*:*:*:*0.4.0.1 alphaVulnerabletorproject
  • cpe:2.3:a:torproject:tor:0.3.5.1:alpha:*:*:*:*:*:* Versions 0.3.5.1 alpha Vulnerable ·torproject
  • cpe:2.3:a:torproject:tor:0.3.5.2:alpha:*:*:*:*:*:* Versions 0.3.5.2 alpha Vulnerable ·torproject
  • cpe:2.3:a:torproject:tor:0.3.5.3:alpha:*:*:*:*:*:* Versions 0.3.5.3 alpha Vulnerable ·torproject
  • cpe:2.3:a:torproject:tor:0.3.5.4:alpha:*:*:*:*:*:* Versions 0.3.5.4 alpha Vulnerable ·torproject
  • cpe:2.3:a:torproject:tor:0.3.5.5:alpha:*:*:*:*:*:* Versions 0.3.5.5 alpha Vulnerable ·torproject
  • cpe:2.3:a:torproject:tor:0.3.5.6:rc:*:*:*:*:*:* Versions 0.3.5.6 rc Vulnerable ·torproject
  • cpe:2.3:a:torproject:tor:0.3.5.7:*:*:*:*:*:*:* Versions 0.3.5.7 Vulnerable ·torproject
  • cpe:2.3:a:torproject:tor:0.4.0.1:alpha:*:*:*:*:*:* Versions 0.4.0.1 alpha Vulnerable ·torproject

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2019-8955
  2. 2026-10-03 Alias added: GHSA-h3x5-p32h-w7q2

References

Advisory 3

  • 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
See all 47 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences