- 7.5HighCVSS base score
- 3.3%Exploitation in 30 daysEPSS · top 11% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In ZeroMQ before version 4.3.3, there is a denial-of-service vulnerability. Users with TCP transport public endpoints, even with CURVE/ZAP enabled, are impacted. If a raw TCP socket is opened and connected to an endpoint that is fully configured with CURVE/ZAP, legitimate clients will not be able to exchange any message. Handshakes complete successfully, and messages are delivered to the library, but the server application never receives them. This is patched in version 4.3.3.
Timeline
ID reserved
By GitHub_M
- 3 months later
· 3 months later
Published
- 4 years later
· 4 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 |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 3.3% · top 11% of all CVEs (11 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
References
References7
- https://github.com/zeromq/libzmq/security/advisories/GHSA-25wp-cf8g-938m (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://github.com/zeromq/libzmq/pull/3913 (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/zeromq/libzmq/pull/3973 (opens in a new tab)x_refsource_MISCx_transferred
- GLSA-202009-12 (opens in a new tab)vendor-advisoryx_refsource_GENTOOx_transferred
- FEDORA-2020-08402f4071 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- FEDORA-2020-5460fcf6bd (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- [debian-lts-announce] 20201110 [SECURITY] [DLA 2443-1] zeromq3 security update (opens in a new tab)mailing-listx_refsource_MLISTx_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-2020-7240 (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-2020-15166)Record last updated .