CVE-2026-52921
5.5 · MEDIUMOverview
CVE-2026-52921 is a medium-severity vulnerability affecting linux linux_kernel. It was published on June 24, 2026 and has a CVSS 3.1 base score of 5.5 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 5.5, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
Technical Description
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ipset: stop hash:* range iteration at end
The following hash set variants:
hash:ip,mark
hash:ip,port
hash:ip,port,ip
hash:ip,port,net
iterate IPv4 ranges with a 32-bit iterator.
The iterator must stop once the last address in the requested range has
been processed. Advancing it once more can move the traversal state past
the end of the request, so a later retry may continue from an unintended
position.
Handle the iterator increment explicitly at the end of the loop and stop
once the upper bound has been processed. This keeps the existing retry
behaviour intact for valid ranges while preventing traversal from
continuing past the original boundary.
Remediation
Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| linux | linux_kernel | >= 4.14.1, < 5.10.258 | Affected |
References
Frequently Asked Questions
What is CVE-2026-52921?
CVE-2026-52921 is a medium-severity vulnerability affecting linux linux_kernel. It was published on June 24, 2026 and has a CVSS 3.1 base score of 5.5 (MEDIUM).
How severe is CVE-2026-52921?
This vulnerability has a CVSS 3.1 base score of 5.5, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2026-52921?
Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-52921?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-52921 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
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Browser-based exploitation validates findings with real proof-of-concept.
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