GHSA-MP33-36GG-V9H7
Vulnerability from github – Published: 2026-04-13 15:31 – Updated: 2026-04-18 09:30In 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.
{
"affected": [],
"aliases": [
"CVE-2026-31428"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-04-13T14:16:12Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nfnetlink_log: fix uninitialized padding leak in NFULA_PAYLOAD\n\n__build_packet_message() manually constructs the NFULA_PAYLOAD netlink\nattribute using skb_put() and skb_copy_bits(), bypassing the standard\nnla_reserve()/nla_put() helpers. While nla_total_size(data_len) bytes\nare allocated (including NLA alignment padding), only data_len bytes\nof actual packet data are copied. The trailing nla_padlen(data_len)\nbytes (1-3 when data_len is not 4-byte aligned) are never initialized,\nleaking stale heap contents to userspace via the NFLOG netlink socket.\n\nReplace the manual attribute construction with nla_reserve(), which\nhandles the tailroom check, header setup, and padding zeroing via\n__nla_reserve(). The subsequent skb_copy_bits() fills in the payload\ndata on top of the properly initialized attribute.",
"id": "GHSA-mp33-36gg-v9h7",
"modified": "2026-04-18T09:30:20Z",
"published": "2026-04-13T15:31:42Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31428"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/21d8efda029948d3666b0db5afcc0d36c0984aae"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/52025ebaa29f4eb4ed8bf92ce83a68f24ab7fdf7"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7eff72968161fb8ddb26113344de3b92fb7d7ef5"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7f3e5d72455936f42709116fabeca3bb216cda62"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a2f6ff3444b663d6cfa63eadd61327a18592885a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a8365d1064ded323797c5e28e91070c52f44b76c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c9f6c51d36482805ac3ffadb9663fe775a13e926"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/fc961dd7272b5e4a462999635e44a4770d7f2482"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.