CVE-2026-43329
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.14%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.14% probability · 4th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-770
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/504c9456699dcf4d15195ef34a0fa94a80bfc877Patch
- https://git.kernel.org/stable/c/5382bb03e9c33b089d60788478b922a2dca284ccPatch
- https://git.kernel.org/stable/c/57c78bd2e2dd08897acd35b2bf8bcef322e36f5ePatch
- https://git.kernel.org/stable/c/76522fcdbc3a02b568f5d957f7e66fc194abb893Patch
- https://git.kernel.org/stable/c/879959a7a2be814dd57568655eafa3d8f4d0309ePatch
- https://git.kernel.org/stable/c/ead66c77303f760f6c30be96e2e20d5a77cef614Patch
- https://git.kernel.org/stable/c/fe9018d3e94329f1951b00805a8640bc06f56eadPatch
- https://access.redhat.com/errata/RHSA-2026:23329
- https://access.redhat.com/errata/RHSA-2026:26427
- https://access.redhat.com/errata/RHSA-2026:26428
- https://access.redhat.com/errata/RHSA-2026:27713
- https://access.redhat.com/errata/RHSA-2026:30848
- https://access.redhat.com/errata/RHSA-2026:33215
- https://access.redhat.com/errata/RHSA-2026:33899
- https://access.redhat.com/errata/RHSA-2026:33900
- https://access.redhat.com/errata/RHSA-2026:34094
- https://access.redhat.com/errata/RHSA-2026:34095
- https://access.redhat.com/errata/RHSA-2026:35863
- https://access.redhat.com/errata/RHSA-2026:35896
- https://access.redhat.com/errata/RHSA-2026:40764
- https://access.redhat.com/errata/RHSA-2026:43252
- https://access.redhat.com/errata/RHSA-2026:44230
- https://access.redhat.com/errata/RHSA-2026:44231
- https://access.redhat.com/errata/RHSA-2026:44259
- https://access.redhat.com/errata/RHSA-2026:44262
- https://access.redhat.com/errata/RHSA-2026:47702
- https://access.redhat.com/errata/RHSA-2026:47727
- https://access.redhat.com/errata/RHSA-2026:54187
- https://access.redhat.com/errata/RHSA-2026:55618
- https://access.redhat.com/errata/RHSA-2026:55761
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.