CVE-2018-5391 | The Linux kernel, versions 3.9+, IP implementation is vulnerable to denial of service conditions with low rates of specially modified packets

The Linux kernel, versions 3.9+, is vulnerable to a denial of service attack with low rates of specially modified packets targeting IP fragment re-assembly. An attacker may cause a denial of service condition by sending specially crafted IP fragments. Various vulnerabilities in IP fragmentation have been discovered and fixed over the years. The current vulnerability (CVE-2018-5391) became exploitable in the Linux kernel with the increase of the IP fragment reassembly queue size.

Published: 2018-09-06 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-5391 is rated Moderate Risk (64.6/100): CVSS High severity, with high exploitation likelihood (EPSS 24.57%, 98th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2018-5391

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-24 24.15% 24.57% +0.43%
2 2026-06-15 4.26% 24.15% +19.89%
3 2026-05-15 — 4.26% —

Full EPSS history (33 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-5391

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
7.8 2.0 HIGH
AV:N/AC:L/Au:N/C:N/I:N/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:C)
Complete availability impact.
 10.0 6.9 [email protected]

Weakness enumeration for CVE-2018-5391

OS Trackers for CVE-2018-5391

vendor priority summary link
debian not yet assigned CVE-2018-5391 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2018-5391
redhat high — https://access.redhat.com/security/cve/CVE-2018-5391
suse medium CVE-2018-5391 severity moderate: SUSE including 256 source package names (bpftool-3.10.0-957.el7, cluster-md-kmp-azure-4.12.14-5.13.1, …), 480 product×package rows across 62 product lines (SLES for SAP Applications 11 SP3, SUSE CaaS Platform 3.0, … (62 product lines)): Fixed 441, Known Not Affected 39. https://www.suse.com/security/cve/CVE-2018-5391/
ubuntu high CVE-2018-5391 high priority: Ubuntu including 77 source packages (linux, linux-aws, …), 620 status rows across 10 suites (bionic, cosmic, disco, focal, jammy, noble, oracular, trusty, upstream, xenial): DNE 392, not-affected 120, released 98, ignored 10. https://ubuntu.com/security/CVE-2018-5391

Affected software / configurations for CVE-2018-5391

Vendor Product Version Raw CPE
linux linux_kernel >= 3.9, <= 4.18 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
redhat enterprise_linux_desktop 6.0 cpe:2.3:o:redhat:enterprise_linux_desktop:6.0:*:*:*:*:*:*:*
redhat enterprise_linux_desktop 7.0 cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_server 6.0 cpe:2.3:o:redhat:enterprise_linux_server:6.0:*:*:*:*:*:*:*
redhat enterprise_linux_server 7.0 cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 6.4 cpe:2.3:o:redhat:enterprise_linux_server_aus:6.4:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 6.5 cpe:2.3:o:redhat:enterprise_linux_server_aus:6.5:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 6.6 cpe:2.3:o:redhat:enterprise_linux_server_aus:6.6:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 7.2 cpe:2.3:o:redhat:enterprise_linux_server_aus:7.2:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 7.3 cpe:2.3:o:redhat:enterprise_linux_server_aus:7.3:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 7.4 cpe:2.3:o:redhat:enterprise_linux_server_aus:7.4:*:*:*:*:*:*:*
redhat enterprise_linux_server_eus 6.7 cpe:2.3:o:redhat:enterprise_linux_server_eus:6.7:*:*:*:*:*:*:*
redhat enterprise_linux_server_eus 7.3 cpe:2.3:o:redhat:enterprise_linux_server_eus:7.3:*:*:*:*:*:*:*
redhat enterprise_linux_server_eus 7.4 cpe:2.3:o:redhat:enterprise_linux_server_eus:7.4:*:*:*:*:*:*:*
redhat enterprise_linux_server_eus 7.5 cpe:2.3:o:redhat:enterprise_linux_server_eus:7.5:*:*:*:*:*:*:*
redhat enterprise_linux_server_tus 6.6 cpe:2.3:o:redhat:enterprise_linux_server_tus:6.6:*:*:*:*:*:*:*
redhat enterprise_linux_server_tus 7.2 cpe:2.3:o:redhat:enterprise_linux_server_tus:7.2:*:*:*:*:*:*:*
redhat enterprise_linux_server_tus 7.3 cpe:2.3:o:redhat:enterprise_linux_server_tus:7.3:*:*:*:*:*:*:*
redhat enterprise_linux_server_tus 7.4 cpe:2.3:o:redhat:enterprise_linux_server_tus:7.4:*:*:*:*:*:*:*
redhat enterprise_linux_workstation 6.0 cpe:2.3:o:redhat:enterprise_linux_workstation:6.0:*:*:*:*:*:*:*
redhat enterprise_linux_workstation 7.0 cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
canonical ubuntu_linux 12.04 cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:esm:*:*:*
canonical ubuntu_linux 14.04 cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
microsoft windows_10 — cpe:2.3:o:microsoft:windows_10:-:*:*:*:*:*:*:*
microsoft windows_10 1607 cpe:2.3:o:microsoft:windows_10:1607:*:*:*:*:*:*:*
microsoft windows_10 1703 cpe:2.3:o:microsoft:windows_10:1703:*:*:*:*:*:*:*
microsoft windows_10 1709 cpe:2.3:o:microsoft:windows_10:1709:*:*:*:*:*:*:*
microsoft windows_10 1803 cpe:2.3:o:microsoft:windows_10:1803:*:*:*:*:*:*:*
microsoft windows_7 — cpe:2.3:o:microsoft:windows_7:-:sp1:*:*:*:*:*:*
microsoft windows_8.1 — cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:*:*
microsoft windows_rt_8.1 — cpe:2.3:o:microsoft:windows_rt_8.1:-:*:*:*:*:*:*:*
microsoft windows_server_2008 — cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:*:*
microsoft windows_server_2008 r2 cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:*
microsoft windows_server_2008 r2 cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:itanium:*:*
microsoft windows_server_2012 — cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*
microsoft windows_server_2012 r2 cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
microsoft windows_server_2016 — cpe:2.3:o:microsoft:windows_server_2016:-:*:*:*:*:*:*:*
microsoft windows_server_2016 1709 cpe:2.3:o:microsoft:windows_server_2016:1709:*:*:*:*:*:*:*
microsoft windows_server_2016 1803 cpe:2.3:o:microsoft:windows_server_2016:1803:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager >= 11.5.1, < 11.6.5.1 cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager >= 12.1.0, < 12.1.5 cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager >= 13.0.0, < 13.1.3 cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager >= 14.0.0, < 14.0.1.1 cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager >= 14.1.0, < 14.1.2.4 cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*
f5 big-ip_advanced_firewall_manager >= 11.5.1, < 11.6.5.1 cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:*
f5 big-ip_advanced_firewall_manager >= 12.1.0, < 12.1.5 cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:*
f5 big-ip_advanced_firewall_manager >= 13.0.0, < 13.1.3 cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:*
f5 big-ip_advanced_firewall_manager >= 14.0.0, < 14.0.1.1 cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:*
f5 big-ip_advanced_firewall_manager >= 14.1.0, < 14.1.2.4 cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:*
f5 big-ip_analytics >= 11.5.1, < 11.6.5.1 cpe:2.3:a:f5:big-ip_analytics:*:*:*:*:*:*:*:*
f5 big-ip_analytics >= 12.1.0, < 12.1.5 cpe:2.3:a:f5:big-ip_analytics:*:*:*:*:*:*:*:*
f5 big-ip_analytics >= 13.0.0, < 13.1.3 cpe:2.3:a:f5:big-ip_analytics:*:*:*:*:*:*:*:*
f5 big-ip_analytics >= 14.0.0, < 14.0.1.1 cpe:2.3:a:f5:big-ip_analytics:*:*:*:*:*:*:*:*
f5 big-ip_analytics >= 14.1.0, < 14.1.2.4 cpe:2.3:a:f5:big-ip_analytics:*:*:*:*:*:*:*:*
f5 big-ip_application_acceleration_manager >= 11.5.1, < 11.6.5.1 cpe:2.3:a:f5:big-ip_application_acceleration_manager:*:*:*:*:*:*:*:*
f5 big-ip_application_acceleration_manager >= 12.1.0, < 12.1.5 cpe:2.3:a:f5:big-ip_application_acceleration_manager:*:*:*:*:*:*:*:*
f5 big-ip_application_acceleration_manager >= 13.0.0, < 13.1.3 cpe:2.3:a:f5:big-ip_application_acceleration_manager:*:*:*:*:*:*:*:*
f5 big-ip_application_acceleration_manager >= 14.0.0, < 14.0.1.1 cpe:2.3:a:f5:big-ip_application_acceleration_manager:*:*:*:*:*:*:*:*
f5 big-ip_application_acceleration_manager >= 14.1.0, < 14.1.2.4 cpe:2.3:a:f5:big-ip_application_acceleration_manager:*:*:*:*:*:*:*:*
f5 big-ip_application_security_manager >= 11.5.1, < 11.6.5.1 cpe:2.3:a:f5:big-ip_application_security_manager:*:*:*:*:*:*:*:*
f5 big-ip_application_security_manager >= 12.1.0, < 12.1.5 cpe:2.3:a:f5:big-ip_application_security_manager:*:*:*:*:*:*:*:*
f5 big-ip_application_security_manager >= 13.0.0, < 13.1.3 cpe:2.3:a:f5:big-ip_application_security_manager:*:*:*:*:*:*:*:*
f5 big-ip_application_security_manager >= 14.0.0, < 14.0.1.1 cpe:2.3:a:f5:big-ip_application_security_manager:*:*:*:*:*:*:*:*
f5 big-ip_application_security_manager >= 14.1.0, < 14.1.2.4 cpe:2.3:a:f5:big-ip_application_security_manager:*:*:*:*:*:*:*:*
f5 big-ip_domain_name_system >= 11.5.1, < 11.6.5.1 cpe:2.3:a:f5:big-ip_domain_name_system:*:*:*:*:*:*:*:*
f5 big-ip_domain_name_system >= 12.1.0, < 12.1.5 cpe:2.3:a:f5:big-ip_domain_name_system:*:*:*:*:*:*:*:*
f5 big-ip_domain_name_system >= 13.0.0, < 13.1.3 cpe:2.3:a:f5:big-ip_domain_name_system:*:*:*:*:*:*:*:*
f5 big-ip_domain_name_system >= 14.0.0, < 14.0.1.1 cpe:2.3:a:f5:big-ip_domain_name_system:*:*:*:*:*:*:*:*
f5 big-ip_domain_name_system >= 14.1.0, < 14.1.2.4 cpe:2.3:a:f5:big-ip_domain_name_system:*:*:*:*:*:*:*:*
f5 big-ip_edge_gateway >= 11.5.1, < 11.6.5.1 cpe:2.3:a:f5:big-ip_edge_gateway:*:*:*:*:*:*:*:*
f5 big-ip_edge_gateway >= 12.1.0, < 12.1.5 cpe:2.3:a:f5:big-ip_edge_gateway:*:*:*:*:*:*:*:*
f5 big-ip_edge_gateway >= 13.0.0, < 13.1.3 cpe:2.3:a:f5:big-ip_edge_gateway:*:*:*:*:*:*:*:*
f5 big-ip_edge_gateway >= 14.0.0, < 14.0.1.1 cpe:2.3:a:f5:big-ip_edge_gateway:*:*:*:*:*:*:*:*
f5 big-ip_edge_gateway >= 14.1.0, < 14.1.2.4 cpe:2.3:a:f5:big-ip_edge_gateway:*:*:*:*:*:*:*:*
f5 big-ip_fraud_protection_service >= 11.5.1, < 11.6.5.1 cpe:2.3:a:f5:big-ip_fraud_protection_service:*:*:*:*:*:*:*:*
f5 big-ip_fraud_protection_service >= 12.1.0, < 12.1.5 cpe:2.3:a:f5:big-ip_fraud_protection_service:*:*:*:*:*:*:*:*

References for CVE-2018-5391

URL Tags
http://www.arubanetworks.com/assets/alert/ARUBA-PSA-2018-004.txt Third Party Advisory
http://www.huawei.com/en/psirt/security-advisories/huawei-sa-20200115-01-linux-en Broken Link
http://www.openwall.com/lists/oss-security/2019/06/28/2 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2019/07/06/3 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2019/07/06/4 Mailing List Third Party Advisory
http://www.securityfocus.com/bid/105108 Third Party Advisory VDB Entry
http://www.securitytracker.com/id/1041476 Third Party Advisory VDB Entry
http://www.securitytracker.com/id/1041637 Third Party Advisory VDB Entry
https://access.redhat.com/errata/RHSA-2018:2785 Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:2791 Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:2846 Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:2924 Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:2925 Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:2933 Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:2948 Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:3083 Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:3096 Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:3459 Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:3540 Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:3586 Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:3590 Third Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-377115.pdf Third Party Advisory
https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/commit/?id=c30f1fc041b74ecdb072dd44f858750414b8b19f Patch Vendor Advisory
https://lists.debian.org/debian-lts-announce/2018/08/msg00014.html Mailing List Mitigation Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/03/msg00017.html Mailing List Third Party Advisory
https://security.netapp.com/advisory/ntap-20181003-0002/ Third Party Advisory
https://support.f5.com/csp/article/K74374841?utm_source=f5support&amp%3Butm_medium=RSS
https://usn.ubuntu.com/3740-1/ Third Party Advisory
https://usn.ubuntu.com/3740-2/ Third Party Advisory
https://usn.ubuntu.com/3741-1/ Third Party Advisory
https://usn.ubuntu.com/3741-2/ Third Party Advisory
https://usn.ubuntu.com/3742-1/ Third Party Advisory
https://usn.ubuntu.com/3742-2/ Third Party Advisory
https://www.debian.org/security/2018/dsa-4272 Mitigation Third Party Advisory
https://www.kb.cert.org/vuls/id/641765 Third Party Advisory US Government Resource
cvelogic Threat Intelligence