VulnerabilityPublished 24 Jun 2026Updated 6 Nov 2026

CVE-2026-52921: Linux kernel · netfilter: ipset: stop hash:* range iteration at end

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in c281e018af98df91827d65bec00f4956c00a1b02 : update Linux kernel when convenient.

Data as of 6 Nov 2026, 16:49 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-11-06.

Patch

Available – fixed in c281e018af98df91827d65bec00f4956c00a1b02, be75218fadea22e59c8673db212f29c681bf45bb, 383418c20e69f5761b6ec5238f599423f4fb77fb +5

Exploitation evidence

Disclosed: evidence found.
CVE published 24 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 48596a8ddc46f96afb6a2cd72787cb15d6bb01fc, < c281e018af98df91827d65bec00f4956c00a1b02	Fixed in c281e018af98df91827d65bec00f4956c00a1b02
LinuxLinux	Affected ≥ 48596a8ddc46f96afb6a2cd72787cb15d6bb01fc, < be75218fadea22e59c8673db212f29c681bf45bb	Fixed in be75218fadea22e59c8673db212f29c681bf45bb
LinuxLinux	Affected ≥ 48596a8ddc46f96afb6a2cd72787cb15d6bb01fc, < 383418c20e69f5761b6ec5238f599423f4fb77fb	Fixed in 383418c20e69f5761b6ec5238f599423f4fb77fb
LinuxLinux	Affected ≥ 48596a8ddc46f96afb6a2cd72787cb15d6bb01fc, < 952e988163c2ab9939c3db9f0f8e77af6a1bb436	Fixed in 952e988163c2ab9939c3db9f0f8e77af6a1bb436
LinuxLinux	Affected ≥ 48596a8ddc46f96afb6a2cd72787cb15d6bb01fc, < 02f75f041a93ea045834da89cd3234f4c1d749b4	Fixed in 02f75f041a93ea045834da89cd3234f4c1d749b4
LinuxLinux	Affected ≥ 48596a8ddc46f96afb6a2cd72787cb15d6bb01fc, < 0d7b33ace701fe397e6e4de145f32e098178d901	Fixed in 0d7b33ace701fe397e6e4de145f32e098178d901

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.

References

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