CVE-2026-31428
In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_log: fix uninitialized padding leak in NFULA_PAYLOAD __build_packet_message() manually constructs the NFULA_PAYLOAD netlink attribute using skb_put() and…
Does this matter?
Lower severity and a low EPSS score (0.13%). Track it; it rarely justifies an emergency change on its own.
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_log: fix uninitialized padding leak in NFULA_PAYLOAD __build_packet_message() manually constructs the NFULA_PAYLOAD netlink attribute using skb_put() and skb_copy_bits(), bypassing the standard nla_reserve()/nla_put() helpers. While nla_total_size(data_len) bytes are allocated (including NLA alignment padding), only data_len bytes of actual packet data are copied. The trailing nla_padlen(data_len) bytes (1-3 when data_len is not 4-byte aligned) are never initialized, leaking stale heap contents to userspace via the NFLOG netlink socket. Replace the manual attribute construction with nla_reserve(), which handles the tailroom check, header setup, and padding zeroing via __nla_reserve(). The subsequent skb_copy_bits() fills in the payload data on top of the properly initialized attribute.
- CVSS 3.1
- 5.5 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.13% probability · 3th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-908
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/21d8efda029948d3666b0db5afcc0d36c0984aaePatch
- https://git.kernel.org/stable/c/52025ebaa29f4eb4ed8bf92ce83a68f24ab7fdf7Patch
- https://git.kernel.org/stable/c/7eff72968161fb8ddb26113344de3b92fb7d7ef5Patch
- https://git.kernel.org/stable/c/7f3e5d72455936f42709116fabeca3bb216cda62Patch
- https://git.kernel.org/stable/c/a2f6ff3444b663d6cfa63eadd61327a18592885aPatch
- https://git.kernel.org/stable/c/a8365d1064ded323797c5e28e91070c52f44b76cPatch
- https://git.kernel.org/stable/c/c9f6c51d36482805ac3ffadb9663fe775a13e926Patch
- https://git.kernel.org/stable/c/fc961dd7272b5e4a462999635e44a4770d7f2482Patch
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.