CVE-2026-31428
What it is
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.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.1% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.1% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.1% · EPSS, next 30 days
- Weakness
- CWE-908
- Record status
- Modified
Affected
- Linux Kernel < 5.10.253
- Linux Kernel < 5.15.203
- Linux Kernel < 6.1.168
- Linux Kernel < 6.6.131
- Linux Kernel < 6.12.80
- Linux Kernel < 6.18.21
- Linux Kernel < 6.19.11
- Linux Kernel 7.0
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-31428.md and follow it. Check whether this project is affected by CVE-2026-31428. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/21d8efda029948d3666b0db5afcc0d36c0984aae
- https://git.kernel.org/stable/c/52025ebaa29f4eb4ed8bf92ce83a68f24ab7fdf7
- https://git.kernel.org/stable/c/7eff72968161fb8ddb26113344de3b92fb7d7ef5
- https://git.kernel.org/stable/c/7f3e5d72455936f42709116fabeca3bb216cda62
- https://git.kernel.org/stable/c/a2f6ff3444b663d6cfa63eadd61327a18592885a
- https://git.kernel.org/stable/c/a8365d1064ded323797c5e28e91070c52f44b76c
- https://git.kernel.org/stable/c/c9f6c51d36482805ac3ffadb9663fe775a13e926
- https://git.kernel.org/stable/c/fc961dd7272b5e4a462999635e44a4770d7f2482
References
- https://git.kernel.org/stable/c/21d8efda029948d3666b0db5afcc0d36c0984aae
- https://git.kernel.org/stable/c/52025ebaa29f4eb4ed8bf92ce83a68f24ab7fdf7
- https://git.kernel.org/stable/c/7eff72968161fb8ddb26113344de3b92fb7d7ef5
- https://git.kernel.org/stable/c/7f3e5d72455936f42709116fabeca3bb216cda62
- https://git.kernel.org/stable/c/a2f6ff3444b663d6cfa63eadd61327a18592885a
- https://git.kernel.org/stable/c/a8365d1064ded323797c5e28e91070c52f44b76c
- https://git.kernel.org/stable/c/c9f6c51d36482805ac3ffadb9663fe775a13e926
- https://git.kernel.org/stable/c/fc961dd7272b5e4a462999635e44a4770d7f2482
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html