cbcvebase.
CVE-2026-43329
published 2026-05-08

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…

PriorityP339high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
EPSS
0.14%
3.8th percentile
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.

Affected

21 ranges
VendorProductVersion rangeFixed in
linuxlinux——
linuxlinux>= c29f74e0df7a02b8303bcdce93a7c0132d62577a < ead66c77303f760f6c30be96e2e20d5a77cef614ead66c77303f760f6c30be96e2e20d5a77cef614
linuxlinux>= c29f74e0df7a02b8303bcdce93a7c0132d62577a < fe9018d3e94329f1951b00805a8640bc06f56eadfe9018d3e94329f1951b00805a8640bc06f56ead
linuxlinux>= c29f74e0df7a02b8303bcdce93a7c0132d62577a < 5382bb03e9c33b089d60788478b922a2dca284cc5382bb03e9c33b089d60788478b922a2dca284cc
linuxlinux>= c29f74e0df7a02b8303bcdce93a7c0132d62577a < 57c78bd2e2dd08897acd35b2bf8bcef322e36f5e57c78bd2e2dd08897acd35b2bf8bcef322e36f5e
linuxlinux>= c29f74e0df7a02b8303bcdce93a7c0132d62577a < 504c9456699dcf4d15195ef34a0fa94a80bfc877504c9456699dcf4d15195ef34a0fa94a80bfc877
linuxlinux>= c29f74e0df7a02b8303bcdce93a7c0132d62577a < 879959a7a2be814dd57568655eafa3d8f4d0309e879959a7a2be814dd57568655eafa3d8f4d0309e
linuxlinux>= c29f74e0df7a02b8303bcdce93a7c0132d62577a < 76522fcdbc3a02b568f5d957f7e66fc194abb89376522fcdbc3a02b568f5d957f7e66fc194abb893
linuxlinux_kernel——
linuxlinux_kernel——
linuxlinux_kernel——
linuxlinux_kernel——
linuxlinux_kernel——
linuxlinux_kernel——
linuxlinux_kernel——
linuxlinux_kernel>= 5.16 < 6.1.1686.1.168
linuxlinux_kernel>= 5.5 < 5.15.2035.15.203
linuxlinux_kernel>= 6.13 < 6.18.226.18.22
linuxlinux_kernel>= 6.19 < 6.19.126.19.12
linuxlinux_kernel>= 6.2 < 6.6.1346.6.134
linuxlinux_kernel>= 6.7 < 6.12.816.12.81

CVSS provenance

nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
vendor_redhat7.8HIGH
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