Vulnerability · 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.
Published Jun 30, 2023 · catalog updated Oct 14, 2026 · linux kernel
Check if you run it
No confirmed exploitation is on record for CVE-2023-1206. EPSS is 0.63%. Act only if a listed version of linux kernel is installed.
- Severity
- Medium5.7
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.63%
- Remediation
- Advisory link
- Affected products
- cpe fedoraproject/fedora · cpe linux/linux kernel · cpe redhat/enterprise linux
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%.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe fedoraproject/fedora38
- cpe linux/linux kernelversion unspecified
- cpe redhat/enterprise linux8.0
- cpe redhat/enterprise linux9.0
How to fix CVE-2023-1206
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2023-1206. EPSS is 0.63%. Act only if a listed version of linux kernel is installed.
Which versions are affected?
Compare what you have installed with redhat/enterprise linux 8.0; redhat/enterprise linux 9.0. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-400: Uncontrolled Resource Consumption. EPSS 0.63%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Jun 30, 2023 · NIST NVD
Detected
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%.
Oct 14, 2026 · NIST NVD
Updated
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%.
Sources
- CVE.orgVulnerability recordCVE-2023-1206
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2023-1206
30-day exploitation probability 0.6%
first.org - NIST NVDVulnerability recordCVE-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 acc
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 16, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.