Back
CVE-2019-8955
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…
- 7.5HighCVSS base score
- 4.6%Exploitation in 30 daysEPSS · top 8.3% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By mitre
- 1 day later
· 1 day later
Published
- 5 years later
· 5 years later
Record updated
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 |
|---|---|---|---|
| NVDNVD · Modified | 3.0 | High7.5 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 4.6% · top 8.3% of all CVEs (11 Nov 2026)
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
n/a
- affected n/a
References
References4
- 107136 (opens in a new tab)vdb-entryx_refsource_BIDx_transferred
- https://trac.torproject.org/projects/tor/ticket/29168 (opens in a new tab)x_refsource_MISCx_transferred
- https://blog.torproject.org/new-releases-tor-0402-alpha-0358-03411-and-03312 (opens in a new tab)x_refsource_MISCx_transferred
- openSUSE-SU-2019:1107 (opens in a new tab)vendor-advisoryx_refsource_SUSEx_transferred
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-2019-18342 (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-2019-8955)Record last updated .