Description
In the Linux kernel, the following vulnerability has been resolved: ipvs: avoid out-of-bounds write in ip_vs_nat_icmp Sashiko warns that local attacker can modify the packet while it is processed by IPVS. Some places read the IP ihl field multiple times which can cause out-of-bounds access. One such place is ip_vs_nat_icmp where we can write after the validated area. Fix it by providing ciph argument just like it is done for IPv6 and use ciph->len as offset to the embedded transport header. Modify some IPv4 header checks by reading the ihl field only once.
References6
- git.kernel.org/stable/c/243d0187ec4c3837b9b0004f18d1068e46115760
- git.kernel.org/stable/c/3b8f79af0e98f27b932b0b416e9c52b692d31ff9
- git.kernel.org/stable/c/3c779b258c9c3c3567af68d4f45c2f751f35bd0e
- git.kernel.org/stable/c/646922a0379496154e8c8faca4f8e2fd9100cacc
- git.kernel.org/stable/c/a69a4b3fff5814d079beff9a1e9d369994b2ed47
- git.kernel.org/stable/c/be65fa324640c7a95e30b146159a2be5cc73f22e
Metrics
- CVSS 3.1
-
7.8
HIGH
Score source: CNA
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 2 · as of 9 November 2026
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.