No exploitation reportedFix available

CVE-2019-18805

Q: Is CVE-2019-18805 actively exploited?

Active exploitation of CVE-2019-18805 has not been confirmed. Its EPSS score was 3.5% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2019-18805?

CVE-2019-18805 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2019-11-07
Fixed in5.0.11 · 4.19.38 · 4.14.115 · 4.9.172 · 4.4.180
WeaknessCWE-190

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

An issue was discovered in net/ipv4/sysctl_net_ipv4.c in the Linux kernel before 5.0.11. There is a net/ipv4/tcp_input.c signed integer overflow in tcp_ack_update_rtt() when userspace writes a very large integer to /proc/sys/net/ipv4/tcp_min_rtt_wlen, leading to a denial of service or possibly unspecified other impact, aka CID-19fad20d15a6.

Timeline

dates in UTC

2019-11-0714:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2019-18805?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2019-18805?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Linux linux kernel

Branch	Affected	Fixed in	Source
5.0	≥ 5.0, < 5.0.11	5.0.11	NVD
4.19	≥ 4.19, < 4.19.38	4.19.38	NVD
4.14	≥ 4.14, < 4.14.115	4.14.115	NVD
4.9	≥ 4.9, < 4.9.172	4.9.172	NVD
4.4	≥ 4.4, < 4.4.180	4.4.180	NVD
5.1	= 5.1	no fix published	NVD

Opensuse leap

Branch	Affected	Fixed in	Source
15.0	= 15.0	no fix published	NVD
15.1	= 15.1	no fix published	NVD

Broadcom fabric operating system

Branch	Affected	Fixed in	Source
—	all versions	no fix published	NVD

14 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update Linux linux kernel to 5.0.11 · 4.19.38 · 4.14.115 · 4.9.172 · 4.4.180

Advisories and patches

cdn.kernel.orgPatch · Vendor Advisory
git.kernel.orgPatch · Vendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.19.8read 2026-10-23
NVDCVSS 2.07.5read 2026-10-23
NVDweakness (CWE)CWE-190read 2026-10-23
FIRST EPSSEPSS score3.5 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: 2019-11-07
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2019-18805?

Is CVE-2019-18805 actively exploited?

Active exploitation of CVE-2019-18805 has not been confirmed. Its EPSS score was 3.5% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2019-18805?

CVE-2019-18805 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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