In the Linux kernel, the following vulnerability has been resolved:

netfilter: flowtable: strictly check for maximum number of actions

The maximum number of flowtable hardware offload actions in IPv6 is:

* ethernet mangling (4 payload actions, 2 for each ethernet address)
* SNAT (4 payload actions)
* DNAT (4 payload actions)
* Double VLAN (4 vlan actions, 2 for popping vlan, and 2 for pushing)
for QinQ.
* Redirect (1 action)

Which makes 17, while the maximum is 16. But act_ct supports for tunnels
actions too. Note that payload action operates at 32-bit word level, so
mangling an IPv6 address takes 4 payload actions.

Update flow_action_entry_next() calls to check for the maximum number of
supported actions.

While at it, rise the maximum number of actions per flow from 16 to 24
so this works fine with IPv6 setups.
Advisories
Source ID Title
Ubuntu USN Ubuntu USN USN-8567-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8574-1 Linux kernel (GCP FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8575-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8576-1 Linux kernel (NVIDIA Tegra) vulnerabilities
Ubuntu USN Ubuntu USN USN-8574-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8595-1 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-8596-1 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-8575-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8576-2 Linux kernel (NVIDIA Tegra) vulnerabilities
Ubuntu USN Ubuntu USN USN-8597-1 Linux kernel (IBM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8575-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8595-2 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8606-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8607-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8608-1 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8609-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8610-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8574-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8595-3 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8619-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-8620-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8620-2 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8620-3 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-8620-4 Linux kernel (Intel IoTG) vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

References
Link Providers
https://access.redhat.com/errata/RHSA-2026:23329 cve-icon
https://access.redhat.com/errata/RHSA-2026:26427 cve-icon
https://access.redhat.com/errata/RHSA-2026:26428 cve-icon
https://access.redhat.com/errata/RHSA-2026:27713 cve-icon
https://access.redhat.com/errata/RHSA-2026:30848 cve-icon
https://access.redhat.com/errata/RHSA-2026:33215 cve-icon
https://access.redhat.com/errata/RHSA-2026:33899 cve-icon
https://access.redhat.com/errata/RHSA-2026:33900 cve-icon
https://access.redhat.com/errata/RHSA-2026:34094 cve-icon
https://access.redhat.com/errata/RHSA-2026:34095 cve-icon
https://access.redhat.com/errata/RHSA-2026:35863 cve-icon
https://access.redhat.com/errata/RHSA-2026:35896 cve-icon
https://access.redhat.com/errata/RHSA-2026:40764 cve-icon
https://access.redhat.com/errata/RHSA-2026:43252 cve-icon
https://access.redhat.com/errata/RHSA-2026:44230 cve-icon
https://access.redhat.com/errata/RHSA-2026:44231 cve-icon
https://access.redhat.com/errata/RHSA-2026:44259 cve-icon
https://access.redhat.com/errata/RHSA-2026:44262 cve-icon
https://access.redhat.com/errata/RHSA-2026:47702 cve-icon
https://access.redhat.com/errata/RHSA-2026:47727 cve-icon
https://access.redhat.com/security/cve/CVE-2026-43329 cve-icon
https://bugzilla.redhat.com/show_bug.cgi?id=2468124 cve-icon
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-43329.mbox cve-icon
https://git.kernel.org/stable/c/504c9456699dcf4d15195ef34a0fa94a80bfc877 cve-icon cve-icon
https://git.kernel.org/stable/c/5382bb03e9c33b089d60788478b922a2dca284cc cve-icon cve-icon
https://git.kernel.org/stable/c/57c78bd2e2dd08897acd35b2bf8bcef322e36f5e cve-icon cve-icon
https://git.kernel.org/stable/c/76522fcdbc3a02b568f5d957f7e66fc194abb893 cve-icon cve-icon
https://git.kernel.org/stable/c/879959a7a2be814dd57568655eafa3d8f4d0309e cve-icon cve-icon
https://git.kernel.org/stable/c/ead66c77303f760f6c30be96e2e20d5a77cef614 cve-icon cve-icon
https://git.kernel.org/stable/c/fe9018d3e94329f1951b00805a8640bc06f56ead cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-43329 cve-icon
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-43329.json cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-43329 cve-icon
History

Mon, 18 May 2026 12:45:00 +0000

Type Values Removed Values Added
Weaknesses NVD-CWE-noinfo
CPEs cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*

Fri, 15 May 2026 14:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-20

Fri, 15 May 2026 12:15:00 +0000


Mon, 11 May 2026 15:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-20

Mon, 11 May 2026 09:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-119
CWE-680

Mon, 11 May 2026 07:45:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}


Fri, 08 May 2026 19:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-119
CWE-680

Fri, 08 May 2026 14:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: netfilter: flowtable: strictly check for maximum number of actions The maximum number of flowtable hardware offload actions in IPv6 is: * ethernet mangling (4 payload actions, 2 for each ethernet address) * SNAT (4 payload actions) * DNAT (4 payload actions) * Double VLAN (4 vlan actions, 2 for popping vlan, and 2 for pushing) for QinQ. * Redirect (1 action) Which makes 17, while the maximum is 16. But act_ct supports for tunnels actions too. Note that payload action operates at 32-bit word level, so mangling an IPv6 address takes 4 payload actions. Update flow_action_entry_next() calls to check for the maximum number of supported actions. While at it, rise the maximum number of actions per flow from 16 to 24 so this works fine with IPv6 setups.
Title netfilter: flowtable: strictly check for maximum number of actions
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-07T12:04:45.304Z

Reserved: 2026-05-01T14:12:56.002Z

Link: CVE-2026-43329

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2026-05-08T14:16:42.520

Modified: 2026-08-07T12:17:54.613

Link: CVE-2026-43329

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-05-08T00:00:00Z

Links: CVE-2026-43329 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-05-18T14:30:06Z

Weaknesses