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NVD / CVE Program· CNA Linux

CVE-2026-72436: netfilter: ipset: Don't use test_bit() in lockless RCU readers in hash types

CriticalCVSS 9.8 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 39/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.71% (FIRST EPSS); higher than 54% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: Linux Linux 3219d74e4536658c937fd878a327257b86ce80dd, 6329d3a9afe715fddda0460cfa46b496d61c2fe0, 7445fe965b7d8756070a40e80f8b73348ccda1d7.

Low priority for now. Upgrade to Linux Linux 3219d74e4536658c937fd878a327257b86ce80dd, 6329d3a9afe715fddda0460cfa46b496d61c2fe0, 7445fe965b7d8756070a40e80f8b73348ccda1d7 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: netfilter: ipset: Don't use test_bit() in lockless RCU readers in hash types Sashiko pointed out that there are a few lockless RCU readers using test_bit() which is a relaxed atomic operation and provides no memory barrier guarantees. Use test_bit_acquire() instead where the operation may run parallel with add/del/gc, i.e. is not one from the next cases - protected by region lock - in a set destroy phase - in a new/temporary set creation phase

Published
Aug 15, 2026
Updated
Oct 16, 2026
EPSS
0.7% · 54th percentile
CWE
—

Report tools

JSON

Action score

39

Monitor

Low priority for now.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.7%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
9.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-72436

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 4.2affected
    • 18f84d41d34fa35d0d64bbaea01fe664553ecc06 and later · before c107233d2ff4fd7cef5d02f9124b99194957a710affected · git
    • 18f84d41d34fa35d0d64bbaea01fe664553ecc06 and later · before 6329d3a9afe715fddda0460cfa46b496d61c2fe0affected · git
    • 18f84d41d34fa35d0d64bbaea01fe664553ecc06 and later · before 7445fe965b7d8756070a40e80f8b73348ccda1d7affected · git
    • 18f84d41d34fa35d0d64bbaea01fe664553ecc06 and later · before c4d257734e91bfcdc71d41843392dd6400b5bb1baffected · git
    • 18f84d41d34fa35d0d64bbaea01fe664553ecc06 and later · before 3219d74e4536658c937fd878a327257b86ce80ddaffected · git
    • 18f84d41d34fa35d0d64bbaea01fe664553ecc06 and later · before e4b4984e28c16406ecb318444dea4a8bf47def3eaffected · git
    • before 4.2not affected · semver
    • 6.1.178 and later · up to and including 6.1.*not affected · semver
    • 6.6.145 and later · up to and including 6.6.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.180-16.1.180-1
Debian:13linuxbefore 6.12.100-16.12.100-1
Debian:14linuxbefore 7.1.5-17.1.5-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-72434Aug 15, 2026 · netfilter: ipset: make sure gc is properly stopped
    31Monitor
  • ← EarlierCVE-2026-72435Aug 15, 2026 · netfilter: ipset: fix order of kfree_rcu() and rcu_assign_pointer()
    31Monitor
  • Later →CVE-2026-72437Aug 15, 2026 · md/raid1: free r1_bio when REQ_NOWAIT is set and read would block on retry
    0Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux3219d74e4536658c937fd878a327257b86ce80ddVendor (CNA)
Linux Linux6329d3a9afe715fddda0460cfa46b496d61c2fe0Vendor (CNA)
Linux Linux7445fe965b7d8756070a40e80f8b73348ccda1d7Vendor (CNA)
Linux Linuxc107233d2ff4fd7cef5d02f9124b99194957a710Vendor (CNA)
Linux Linuxc4d257734e91bfcdc71d41843392dd6400b5bb1bVendor (CNA)
Linux Linuxe4b4984e28c16406ecb318444dea4a8bf47def3eVendor (CNA)
debian:linux6.1.180-1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days+1% in 7 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Not on record for this CVE: patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

References

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records