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CVE-2019-11479Jonathan Looney discovered that the Linux kernel default MSS is hard-coded to 48 bytes. This allows a remote peer to fragment TCP resend…
- 5.3MediumCVSS base score
- 91.3%Exploitation in 30 daysEPSS · top 0.2% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
Jonathan Looney discovered that the Linux kernel default MSS is hard-coded to 48 bytes. This allows a remote peer to fragment TCP resend queues significantly more than if a larger MSS were enforced. A remote attacker could use this to cause a denial of service. This has been fixed in stable kernel releases 4.4.182, 4.9.182, 4.14.127, 4.19.52, 5.1.11, and is fixed in commits 967c05aee439e6e5d7d805e195b3a20ef5c433d6 and 5f3e2bf008c2221478101ee72f5cb4654b9fc363.
Timeline
ID reserved
By canonical
- 56 days later
· 56 days 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 |
|---|---|---|---|
| canonicalCNA (assigner) | 3.0 | Medium5.3 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
| 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)
- 91.3% · top 0.2% of all CVEs (12 Nov 2026)
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.3.
Affected products
- affected 4.4 – < 4.4.182
- affected 4.9 – < 4.9.182
- affected 4.14 – < 4.14.127
- affected 4.19 – < 4.19.52
- affected 5.1 – < 5.1.11
References
References28
- 108818 (opens in a new tab)vdb-entryx_refsource_BIDx_transferred
- VU#905115 (opens in a new tab)third-party-advisoryx_refsource_CERT-VNx_transferred
- RHSA-2019:1594 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- RHSA-2019:1602 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- [oss-security] 20190628 Re: linux-distros membership application - Microsoft (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- USN-4041-2 (opens in a new tab)vendor-advisoryx_refsource_UBUNTUx_transferred
- [oss-security] 20190706 Re: linux-distros membership application - Microsoft (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- [oss-security] 20190706 Re: linux-distros membership application - Microsoft (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- RHSA-2019:1699 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- USN-4041-1 (opens in a new tab)vendor-advisoryx_refsource_UBUNTUx_transferred
- https://www.oracle.com/security-alerts/cpujan2020.html (opens in a new tab)x_refsource_MISCx_transferred
- https://www.oracle.com/security-alerts/cpuoct2020.html (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/Netflix/security-bulletins/blob/master/advisories/third-party/2019-001.md (opens in a new tab)x_refsource_MISCx_transferred
- https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/SACKPanic (opens in a new tab)x_refsource_MISCx_transferred
- https://access.redhat.com/security/vulnerabilities/tcpsack (opens in a new tab)x_refsource_MISCx_transferred
- https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44193 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://www.synology.com/security/advisory/Synology_SA_19_28 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://security.netapp.com/advisory/ntap-20190625-0001/ (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://kc.mcafee.com/corporate/index?page=content&id=SB10287 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://cert-portal.siemens.com/productcert/pdf/ssa-462066.pdf (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://www.us-cert.gov/ics/advisories/icsa-19-253-03 (opens in a new tab)x_refsource_MISCx_transferred
- http://www.arubanetworks.com/assets/alert/ARUBA-PSA-2020-010.txt (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git/commit/?id=5f3e2bf008c2221478101ee72f5cb4654b9fc363 (opens in a new tab)x_refsource_MISCx_transferred
- https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git/commit/?id=967c05aee439e6e5d7d805e195b3a20ef5c433d6 (opens in a new tab)x_refsource_MISCx_transferred
- https://support.f5.com/csp/article/K35421172 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2019-0008 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://support.f5.com/csp/article/K35421172?utm_source=f5support&%3Butm_medium=RSS (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://www.us-cert.gov/ics/advisories/icsma-20-170-06 (opens in a new tab)x_refsource_MISCx_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-2019-3152 (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-2019-11479)Record last updated .