Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nftables: exthdr: fix 4-byte stack OOB write If priv->len is a multiple of 4, then dst[len / 4] can write past the destination array which leads to stack corruption. This construct is necessary to clean the remainder of the register in case ->len is NOT a multiple of the register size, so make it conditional just like nft_payload.c does. The bug was added in 4.1 cycle and then copied/inherited when tcp/sctp and ip option support was added. Bug reported by Zero Day Initiative project (ZDI-CAN-21950, ZDI-CAN-21951, ZDI-CAN-21961).
Affected products
linux: linux kernel
References10
- git.kernel.org/stable/c/1ad7b189cc1411048434e8595ffcbe7873b71082 Patch
- git.kernel.org/stable/c/28a97c43c9e32f437ebb8d6126f9bb7f3ca9521a Patch
- git.kernel.org/stable/c/a7d86a77c33ba1c357a7504341172cc1507f0698 Patch
- git.kernel.org/stable/c/c8f292322ff16b9a2272a67de396c09a50e09dce Patch
- git.kernel.org/stable/c/cf39c4f77a773a547ac2bcf30ecdd303bb0c80cb Patch
- git.kernel.org/stable/c/d9ebfc0f21377690837ebbd119e679243e0099cc Patch
- git.kernel.org/stable/c/fd94d9dadee58e09b49075240fe83423eb1dcd36 Patch
- git.kernel.org/stable/c/1ad7b189cc1411048434e8595ffcbe7873b71082 Patch
- git.kernel.org/stable/c/28a97c43c9e32f437ebb8d6126f9bb7f3ca9521a Patch
- git.kernel.org/stable/c/a7d86a77c33ba1c357a7504341172cc1507f0698 Patch
Metrics
- CVSS 3.1
-
7.1
HIGH
Score source: NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H - EPSS — exploit probability
- 1% percentile: 52 · as of 5 November 2026
- CWE
- CWE-787
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.