CVE-2025-4444Tor Onion Service Descriptor resource consumption
- 6.3MediumCVSS base score
- 0.47%Exploitation in 30 daysEPSS · top 58% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. CISA's SSVC rates its exploitation: a proof of concept is public.
Timeline
ID reserved
By VulDB
- 4 months later
· 4 months later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| VulDBCNA (assigner) | 4.0 | Medium6.3 | 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 |
| VulDBCNA (assigner) | 3.1 | Low3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L/E:X/RL:O/RC:C |
| VulDBCNA (assigner) | 3.0 | Low3.7 | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L/E:X/RL:O/RC:C |
| VulDBCNA (assigner) | 2.0 | Low2.6 | AV:N/AC:H/Au:N/C:N/I:N/A:P/E:ND/RL:OF/RC:C |
| NVDNVD · Deferred | 4.0 | Medium6.3 | 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 (exploitation in 30 days)
- 0.47% · top 58% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.3.
Affected products
Tor
- affected 0.4.7.0
- affected 0.4.7.1
- affected 0.4.7.2
- affected 0.4.7.3
- affected 0.4.7.4
- affected 0.4.7.5
- affected 0.4.7.6
- affected 0.4.7.7
- affected 0.4.7.8
- affected 0.4.7.9
- affected 0.4.7.10
- affected 0.4.7.11
- affected 0.4.7.12
- affected 0.4.7.13
- affected 0.4.7.14
- affected 0.4.7.15
- affected 0.4.7.16
- affected 0.4.8.0
- affected 0.4.8.1
- affected 0.4.8.2
- affected 0.4.8.3
- affected 0.4.8.4
- affected 0.4.8.5
- affected 0.4.8.6
- affected 0.4.8.7
- affected 0.4.8.8
- affected 0.4.8.9
- affected 0.4.8.10
- affected 0.4.8.11
- affected 0.4.8.12
- affected 0.4.8.13
- affected 0.4.8.14
- affected 0.4.8.15
- affected 0.4.8.16
- affected 0.4.8.17
- unaffected 0.4.8.18
- unaffected 0.4.9.3-alpha
References
References6
- VDB-324814 | Tor Onion Service Descriptor resource consumption (opens in a new tab)vdb-entry
- VDB-324814 | CTI Indicators (IOB, IOC, TTP) (opens in a new tab)signaturepermissions-required
- Submit #640605 | Tor ≤ 0.4.8 Memory Management vulnerability (opens in a new tab)third-party-advisory
- https://github.com/chunmianwang/Tordos (opens in a new tab)related
- https://gitlab.torproject.org/tpo/core/tor/-/raw/release-0.4.8/ReleaseNotes (opens in a new tab)release-notes
- https://forum.torproject.org/t/alpha-and-stable-release-0-4-8-18-and-0-4-9-3-alpha/20578 (opens in a new tab)patch
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2025-29912 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2025-4444)Record last updated .