What’s Vulnerable › Vulnerabilities

CVE-2025-4444: Tor Onion Service Descriptor resource consumption

• Severity: low (CVSS 3.7 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-09-18 · updated 2026-10-19
• Weakness: CWE-400

Description

A security flaw has been discovered in Tor up to 0.4.7.16/0.4.8.17. Impacted is an unknown function of the component Onion Service Descriptor Handler. Performing manipulation results in resource consumption. The attack may be initiated remotely. The attack's complexity is rated as high. The exploitability is considered difficult. Upgrading to version 0.4.8.18 and 0.4.9.3-alpha is recommended to address this issue. It is recommended to upgrade the affected component.

Affected products

• torproject Tor: 0.4.7.0, 0.4.7.1, 0.4.7.2, 0.4.7.3, 0.4.7.4, 0.4.7.5 (+29)

References

• https://forum.torproject.org/t/alpha-and-stable-release-0-4-8-18-and-0-4-9-3-alpha/20578
• https://github.com/chunmianwang/Tordos
• https://gitlab.torproject.org/tpo/core/tor/-/raw/release-0.4.8/ReleaseNotes
• https://vuldb.com/?ctiid.324814
• https://vuldb.com/?id.324814
• https://vuldb.com/?submit.640605

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