CVE-2019-11477

78

FAUCET Score

CVE-2019-11477 is a high-severity integer overflow vulnerability in the Linux kernel's TCP SACK handling, allowing a remote, unauthenticated attacker to cause a denial of service. This flaw affects various products including Canonical, F5, Ivanti, and Red Hat, and has been patched in stable kernel releases. While no public exploit code exists and it's not on CISA's KEV catalog, its high FAUCET risk score and significant community discussion indicate a notable threat.

Impacted Technologies

Vendor	Product	Version(s)	CPE
		>= 2.6.29, < 3.16.69CPE matchmatch criteria	cpe:2.3:o:linux:linux_kernel::::::::
		>= 3.17, < 4.4.182CPE matchmatch criteria	cpe:2.3:o:linux:linux_kernel::::::::
		>= 4.5, < 4.9.182CPE matchmatch criteria	cpe:2.3:o:linux:linux_kernel::::::::
		>= 4.10, < 4.14.127CPE matchmatch criteria	cpe:2.3:o:linux:linux_kernel::::::::
		>= 4.15, < 4.19.52CPE matchmatch criteria	cpe:2.3:o:linux:linux_kernel::::::::

CVSS Data

CVSS version used by this source: 3.0

7.5HIGH

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

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

Exploitability Score

3.9

Impact Score

3.6

CvssVersion

3.0

Exploit Intelligence

EPSS Score

98.75%

Probability of exploitation in next 30 days

EPSS Percentile

99.9%

Percentile rank of EPSS score among Peer Group

As of 2026-07-27

Model: v2026.06.15

This CVE's current EPSS score of 0.9875 is in the 100th percentile among its peer group of 51,551 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-2019-11477Important

Kernel: tcp: integer overflow while processing SACK blocks allows remote denial of service

References

packetstormsecurity.com / files/153346/Kernel-Live-Patch-Security-Notice-LSN-0052-1.html

Third Party AdvisoryVDB Entry

packetstormsecurity.com / files/154951/Kernel-Live-Patch-Security-Notice-LSN-0058-1.html

Third Party AdvisoryVDB Entry

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

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-2019-0006

Third Party Advisory

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

Third Party Advisory

support.f5.com / csp/article/K78234183

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

Third Party Advisory

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

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

Third Party Advisory

huawei.com / en/psirt/security-advisories/huawei-sa-20191225-01-kernel-en

Third Party Advisory

openwall.com / lists/oss-security/2019/06/20/3

Mailing ListThird 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

openwall.com / lists/oss-security/2019/10/24/1

Mailing ListThird Party Advisory

openwall.com / lists/oss-security/2019/10/29/3

Mailing ListThird Party Advisory

vmware.com / security/advisories/VMSA-2019-0010.html

Third Party Advisory