cbcvebase.
CVE-2026-23254
published 2026-03-18

CVE-2026-23254: In the Linux kernel, the following vulnerability has been resolved: net: gro: fix outer network offset The udp GRO complete stage assumes that all the packets…

PriorityP421medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.11%
1.7th percentile
In the Linux kernel, the following vulnerability has been resolved: net: gro: fix outer network offset The udp GRO complete stage assumes that all the packets inserted the RX have the `encapsulation` flag zeroed. Such assumption is not true, as a few H/W NICs can set such flag when H/W offloading the checksum for an UDP encapsulated traffic, the tun driver can inject GSO packets with UDP encapsulation and the problematic layout can also be created via a veth based setup. Due to the above, in the problematic scenarios, udp4_gro_complete() uses the wrong network offset (inner instead of outer) to compute the outer UDP header pseudo checksum, leading to csum validation errors later on in packet processing. Address the issue always clearing the encapsulation flag at GRO completion time. Such flag will be set again as needed for encapsulated packets by udp_gro_complete().

Affected

44 ranges· showing 25
VendorProductVersion rangeFixed in
debianlinux< linux 6.18.10-1 (forky)linux 6.18.10-1 (forky)
linuxlinux
linuxlinux
linuxlinux>= 5ef31ea5d053a8f493a772ebad3f3ce82c35d845 < b83557bc6f560433fe5d727e241069f8db5ba709b83557bc6f560433fe5d727e241069f8db5ba709
linuxlinux>= 5ef31ea5d053a8f493a772ebad3f3ce82c35d845 < 2e5edb69e5d0e23ef248c56fc977039268c77a7b2e5edb69e5d0e23ef248c56fc977039268c77a7b
linuxlinux>= 5ef31ea5d053a8f493a772ebad3f3ce82c35d845 < 5c2c3c38be396257a6a2e55bd601a12bb97815075c2c3c38be396257a6a2e55bd601a12bb9781507
linuxlinux>= 6.6.31 < 6.6.1246.6.124
linuxlinux>= 6.8.10 < 6.96.9
linuxlinux>= af276a5ac8e938c8b058e3e124073cc1e322d98b < 9d40a85138568696387ef04cd004c64612a708749d40a85138568696387ef04cd004c64612a70874
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.12.73-16.12.73-1
linuxlinux_kernel>= 0 < 6.18.10-16.18.10-1
linuxlinux_kernel>= 0 < 6.6.1246.6.124
linuxlinux_kernel>= 6.13 < 6.18.106.18.10
linuxlinux_kernel>= 6.6.31 < 6.6.1246.6.124
linuxlinux_kernel>= 6.7.0 < 6.12.706.12.70
linuxlinux_kernel>= 6.8.10 < 6.96.9
linuxlinux_kernel>= 6.9.0 < 6.18.106.18.10
linuxlinux_kernel>= 6.9.1 < 6.12.706.12.70
ubuntulinux
ubuntulinux-aws
ubuntulinux-aws-fips
ubuntulinux-azure
ubuntulinux-azure-6.8

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
vendor_ubuntu7.8HIGH
vendor_redhat5.5LOW
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