# CVE-2019-8955: tor: 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 denia...

CVE-2019-8955 is fixed in 2 products on 1 platform, first by tor 0.3.2.10-1ubuntu0.2~esm1, released February 21, 2019. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2019-8955
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0457
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Feb 21, 2019

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | tor Ubuntu 18.04.6 LTS (bionic) | 0.3.2.10-1ubuntu0.2~esm1 | [tor 0.3.2.10-1ubuntu0.2~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-tor-0.3.2.10-1ubuntu0.2-esm1.md) | Feb 21, 2019 |
| Linux | tor-geoipdb Ubuntu 18.04.6 LTS (bionic) | 0.3.2.10-1ubuntu0.2~esm1 | [tor-geoipdb 0.3.2.10-1ubuntu0.2~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-tor-geoipdb-0.3.2.10-1ubuntu0.2-esm1.md) | Feb 21, 2019 |

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Data as of 2026-11-07T18:46:35Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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