CVE-2025-4444: 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....

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.

Metrics

CVSS 3.1

3.7/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS 4.0

6.3/10

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.44%

34.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

References

Timeline

Published: Sep 18, 2025
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2025-4444?

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.

How severe is CVE-2025-4444?

CVE-2025-4444 has a CVSS score of 6.3/10 (MEDIUM severity). The EPSS model estimates a 0.44% probability of exploitation in the next 30 days.

How do I fix CVE-2025-4444?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.