CVE-2026-31428
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | fixed | 6.1.170-1 |
| debian | forky | fixed | 6.19.11-1 |
| debian | sid | fixed | 6.19.11-1 |
| debian | trixie | fixed | 6.12.85-1 |
| debian | bullseye | fixed | 6.1.170-1~deb11u1 |
| linux-kernel | affected | 5.10.253 | |
| linux-kernel | 7.0 | affected | |
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://www.suse.com/security/cve/CVE-2026-31428.html
- https://security-tracker.debian.org/tracker/CVE-2026-31428
CWEs
CWE-908
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.