What is CVE-2018-5703?

CVE-2018-5703 is a critical-severity vulnerability in Linux Kernel, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2018-01-16.

How severe is CVE-2018-5703?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2018-5703 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Buffer overflow in Linux Kernel

CVE-2018-5703

The tcp_v6_syn_recv_sock function in net/ipv6/tcp_ipv6.c in the Linux kernel through 4.14.11 allows attackers to cause a denial of service (slab out-of-bounds write) or possibly have unspecified other impact via vectors involving TLS.

Vulnerability class: Buffer Overflow

Published 2018-01-16 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.026 (84.9th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 85th percentile — 84.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.026 · newest: 0.026 · change: 0.000

Affected products

Linux Kernel

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

Public proof-of-concept exploits

References

groups.google.com/d/msg/syzkaller-bugs/0PBeVnSzfqQ/5eXAlM46BQAJ (Mailing List, Third Party Advisory, Issue Tracking)

Frequently asked questions

What is CVE-2018-5703?: CVE-2018-5703 is a critical-severity vulnerability in Linux Kernel, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2018-01-16.
How severe is CVE-2018-5703?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2018-5703 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.