Linux KernelOperating system · Linux
CVE-2026-52921
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIn 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysisCrafted input drives a loop whose exit condition is never satisfied, hanging the thread and starving the service of the resource it occupies. A single request can be enough to take a worker down. Remediation is bounding iteration counts and validating the conditions that are supposed to terminate the loop.
General guidance for the infinite loop class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Linux KernelOperating system
>= 4.14.1, < 5.10.258>= 5.11, < 5.15.209>= 5.16, < 6.1.175>= 6.2, < 6.6.142>= 6.7, < 6.12.92>= 6.13, < 6.18.34>= 6.19, < 7.0.11= 4.14= 7.1CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped5.10.2585.15.2096.1.175
Upgrade to the next stable kernel release in your version branch: 5.10.258, 5.15.209, 6.1.175, or 6.6.142 depending on your current branch
- Identify currently running Linux kernel version using `uname -r`
- Determine which version range your current kernel falls into (4.14.1-5.10.257, 5.11-5.15.208, 5.16-6.1.174, or 6.2-6.6.141)
- For kernels in range 4.14.1 to 5.10.257: upgrade to kernel 5.10.258 or later
- For kernels in range 5.11 to 5.15.208: upgrade to kernel 5.15.209 or later
- For kernels in range 5.16 to 6.1.174: upgrade to kernel 6.1.175 or later
- For kernels in range 6.2 to 6.6.141: upgrade to kernel 6.6.142 or later
- Reboot the system to load the patched kernel
- Verify the fix is applied by checking the kernel version and confirming the commit 02f75f041a93ea045834da89cd3234f4c1d749b4 is included
Generated from the published advisory — verify against the referenced sources before acting.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-52921 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-52921 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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