CVE-2020-7451
In FreeBSD 12.1-STABLE before r358739, 12.1-RELEASE before 12.1-RELEASE-p3, 11.3-STABLE before r358740, and 11.3-RELEASE before…
- 5.3MediumCVSS base score
- 1.2%Exploitation in 30 daysEPSS · top 32% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In FreeBSD 12.1-STABLE before r358739, 12.1-RELEASE before 12.1-RELEASE-p3, 11.3-STABLE before r358740, and 11.3-RELEASE before 11.3-RELEASE-p7, a TCP SYN-ACK or challenge TCP-ACK segment over IPv6 that is transmitted or retransmitted does not properly initialize the Traffic Class field disclosing one byte of kernel memory over the network.
Timeline
ID reserved
By freebsd
- 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 |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Medium5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
- EPSS (exploitation in 30 days)
- 1.2% · top 32% of all CVEs (11 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.3.
Affected products
FreeBSD
- affected 12.1-STABLE before r358739, 12.1-RELEASE before 12.1-RELEASE-p3, 11.3-STABLE before r358740, 11.3-RELEASE before 11.3-RELEASE-p7
References
References1
- https://security.FreeBSD.org/advisories/FreeBSD-SA-20:04.tcp.asc (opens in a new tab)x_refsource_CONFIRMx_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-2020-28577 (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-2020-7451)Record last updated .