CVE-2019-11479

75

FAUCET Score

CVE-2019-11479 describes a denial-of-service vulnerability in the Linux kernel, affecting various distributions including Canonical, F5, Linux, and Red Hat. The flaw stems from a hard-coded default TCP Maximum Segment Size (MSS) of 48 bytes, allowing remote attackers to significantly fragment TCP resend queues. This vulnerability carries a CVSS score of 7.5 (High), indicating a network-based attack with low complexity that can lead to high availability impact. While there is no evidence of active exploitation, public exploit code, or Metasploit modules, the vulnerability has garnered significant community discussion and media coverage, suggesting awareness among threat actors.

Impacted Technologies

Vendor	Product	Version(s)	CPE
		>= 4.4, < 4.4.182CPE matchmatch criteria	cpe:2.3:o:linux:linux_kernel::::::::
		>= 4.9, < 4.9.182CPE matchmatch criteria	cpe:2.3:o:linux:linux_kernel::::::::
		>= 4.14, < 4.14.127CPE matchmatch criteria	cpe:2.3:o:linux:linux_kernel::::::::
		>= 4.19, < 4.19.52CPE matchmatch criteria	cpe:2.3:o:linux:linux_kernel::::::::
		>= 5.1, < 5.1.11CPE matchmatch criteria	cpe:2.3:o:linux:linux_kernel::::::::

CVSS Data

CVSS version used by this source: 3.0

5.3MEDIUM

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

LOW

Exploitability Score

3.9

Impact Score

1.4

CvssVersion

3.0

Exploit Intelligence

EPSS Score

91.66%

Probability of exploitation in next 30 days

EPSS Percentile

99.8%

Percentile rank of EPSS score among Peer Group

As of 2026-07-28

Model: v2026.06.15

This CVE's current EPSS score of 0.9166 is in the 100th percentile among its peer group of 51,553 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.

Media Mentions

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (22)

github_advisorypatch availablevia nvd_reference

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 6Fixed in: kernel-0:2.6.32-754.15.3.el6

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 6.5 Advanced Update SupportFixed in: kernel-0:2.6.32-431.95.3.el6

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 6.6 Advanced Update SupportFixed in: kernel-0:2.6.32-504.79.3.el6

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 7Fixed in: kernel-rt-0:3.10.0-957.21.3.rt56.935.el7

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 7Fixed in: kernel-0:3.10.0-957.21.3.el7

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 7Fixed in: kernel-alt-0:4.14.0-115.8.2.el7a

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 7.2 Advanced Update SupportFixed in: kernel-0:3.10.0-327.79.2.el7

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 7.2 Telco Extended Update SupportFixed in: kernel-0:3.10.0-327.79.2.el7

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 7.2 Update Services for SAP SolutionsFixed in: kernel-0:3.10.0-327.79.2.el7

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 7.3 Advanced Update SupportFixed in: kernel-0:3.10.0-514.66.2.el7

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 7.3 Telco Extended Update SupportFixed in: kernel-0:3.10.0-514.66.2.el7

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 7.3 Update Services for SAP SolutionsFixed in: kernel-0:3.10.0-514.66.2.el7

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 7.4 Extended Update SupportFixed in: kernel-0:3.10.0-693.50.3.el7

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 7.5 Extended Update SupportFixed in: kernel-0:3.10.0-862.34.2.el7

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 8Fixed in: kernel-rt-0:4.18.0-80.4.2.rt9.152.el8_0

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 8Fixed in: kernel-0:4.18.0-80.4.2.el8_0

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise MRG 2Fixed in: kernel-rt-1:3.10.0-693.50.3.rt56.644.el6rt

redhatpatch availablevia redhat_api

Product: Red Hat Virtualization 4.2 for Red Hat Enterprise Linux 7.6 EUSFixed in: redhat-release-virtualization-host-0:4.2-11.1.el7

redhatpatch availablevia redhat_api

Product: Red Hat Virtualization 4.2 for Red Hat Enterprise Linux 7.6 EUSFixed in: redhat-virtualization-host-0:4.2-20190618.0.el7_6

redhatpatch availablevia redhat_api

Product: Red Hat Virtualization 4 for Red Hat Enterprise Linux 7Fixed in: redhat-release-virtualization-host-0:4.3.4-1.el7ev

redhatpatch availablevia redhat_api

Product: Red Hat Virtualization 4 for Red Hat Enterprise Linux 7Fixed in: redhat-virtualization-host-0:4.3.4-20190620.3.el7_6

Vendor Advisories (1)

redhatCVE-2019-11479Moderate

kernel: tcp: excessive resource consumption for TCP connections with low MSS allows remote denial of service

References

access.redhat.com / errata/RHSA-2019:1594

Third Party Advisory

access.redhat.com / errata/RHSA-2019:1602

Third Party Advisory

access.redhat.com / errata/RHSA-2019:1699

Third Party Advisory

access.redhat.com / security/vulnerabilities/tcpsack

Third Party Advisory

cert-portal.siemens.com / productcert/pdf/ssa-462066.pdf

Third Party Advisory

github.com / Netflix/security-bulletins/blob/master/advisories/third-party/2019-001.md

PatchThird Party Advisory

git.kernel.org / pub/scm/linux/kernel/git/davem/net.git/commit

Mailing ListPatchVendor Advisory

git.kernel.org / pub/scm/linux/kernel/git/davem/net.git/commit

Mailing ListPatchVendor Advisory

kb.pulsesecure.net / articles/Pulse_Security_Advisories/SA44193

Third Party Advisory

kc.mcafee.com / corporate/index

Third Party Advisory

psirt.global.sonicwall.com / vuln-detail/SNWLID-2019-0008

Third Party Advisory

security.netapp.com / advisory/ntap-20190625-0001

Third Party Advisory

support.f5.com / csp/article/K35421172

Third Party Advisory

support.f5.com / csp/article/K35421172

usn.ubuntu.com / 4041-1

Third Party Advisory

usn.ubuntu.com / 4041-2

Third Party Advisory

wiki.ubuntu.com / SecurityTeam/KnowledgeBase/SACKPanic

MitigationThird Party Advisory

kb.cert.org / vuls/id/905115

Third Party AdvisoryUS Government Resource

oracle.com / security-alerts/cpujan2020.html

Third Party Advisory

oracle.com / security-alerts/cpuoct2020.html

synology.com / security/advisory/Synology_SA_19_28

Third Party Advisory

us-cert.gov / ics/advisories/icsa-19-253-03

Third Party AdvisoryUS Government Resource

us-cert.gov / ics/advisories/icsma-20-170-06

Third Party AdvisoryUS Government Resource

arubanetworks.com / assets/alert/ARUBA-PSA-2020-010.txt

Third Party Advisory

openwall.com / lists/oss-security/2019/06/28/2

Mailing ListThird Party Advisory

openwall.com / lists/oss-security/2019/07/06/3

Mailing ListThird Party Advisory

openwall.com / lists/oss-security/2019/07/06/4

Mailing ListThird Party Advisory

securityfocus.com / bid/108818

Third Party AdvisoryVDB Entry