CVE-2026-43329 remediation guide
Linux Linux, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support
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 addres...
Identify the affected asset
Confirm whether Linux Linux, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support is installed, record the deployed version and installation path, and identify exposed interfaces.
- Record the product name, package or appliance identifier, and installed version.
- Identify internet-facing, administrative, API, and internal access paths.
- Preserve the pre-change configuration and relevant service logs.
Validate the affected-version match
Compare the deployed version with the affected range: >= c29f74e0df7a02b8303bcdce93a7c0132d62577a < ead66c77303f760f6c30be96e2e20d5a77cef614, >= c29f74e0df7a02b8303bcdce93a7c0132d62577a < fe9018d3e94329f1951b00805a8640bc06f56ead, >= c29f74e0df7a02b8303bcdce93a7c0132d62577a < 5382bb03e9c33b089d60788478b922a2dca284cc, >= c29f74e0df7a02b8303bcdce93a7c0132d62577a < 57c78bd2e2dd08897acd35b2bf8bcef322e36f5e, >= c29f74e0df7a02b8303bcdce93a7c0132d62577a < 504c9456699dcf4d15195ef34a0fa94a80bfc877, >= c29f74e0df7a02b8303bcdce93a7c0132d62577a < 879959a7a2be814dd57568655eafa3d8f4d0309e, >= c29f74e0df7a02b8303bcdce93a7c0132d62577a < 76522fcdbc3a02b568f5d957f7e66fc194abb893, >= 5.5, >= 5.5 < 5.15.203, >= 5.16 < 6.1.168, >= 6.2 < 6.6.134, >= 6.7 < 6.12.81, >= 6.13 < 6.18.22, >= 6.19 < 6.19.12, 7.0. Treat incomplete inventory results as unresolved.
Prioritize with independent signals
The CVSS severity warrants an early asset and exposure review. Combine this signal with asset criticality, exposure, compensating controls, and business impact.
Apply supported remediation
Follow the vendor advisory or supported update path. Current fixed-version status: 5.15.203, 6.1.168, 6.6.134, 6.12.81, 6.18.22, 6.19.12. Preserve configuration and rollback material before change.
Verify the result
Confirm the resulting version, service health, authentication and access paths, monitoring coverage, and relevant security logs.
- Confirm the expected version and package state.
- Run a functional health check for critical service paths.
- Review authentication, error, application, and security monitoring logs.
- Reassess exposure if the supported fix cannot be applied.
Operational boundary
This page does not replace the vendor advisory, support contract, change-management process, or recovery plan. Do not infer that an asset is unaffected from an incomplete inventory query or a missing fixed-version field.