CVE-2023-1206

A hash collision flaw was found in the IPv6 connection lookup table in the Linux kernel’s IPv6 functionality when a user makes a new kind of SYN flood attack. A user located in the local network or with a high bandwidth connection can increase the CPU usage of the server that accepts IPV6 connections up to 95%.

CVSS 3.1

5.7CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS

0.6% chance of exploitation in the next 30 days; higher than 49% of CVEs (scores of 2026-10-25)

CWE

CWE-400

Published

2023-06-30

Modified

2026-10-14

Record from

the NVD, synced 2026-10-19

Affected

• fedoraproject:fedora
• linux:linux_kernel
• redhat:enterprise_linux

References

• https://bugzilla.redhat.com/show_bug.cgi?id=2175903
• https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html
• https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html
• https://security.netapp.com/advisory/ntap-20230929-0006/
• https://www.debian.org/security/2023/dsa-5480

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