netfilter: nfnetlink_log: fix uninitialized padding leak in NFULA_PAYLOAD (Linux Linux)

CVE-2026-31428
MEDIUM 5.5

At a glance

Source
NVD
EPSS
EPSS 0.13 % · percentile 3 ()
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Modified

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.

Weaknesses (CWE)

  • CWE-908 — Use of Uninitialized Resource

References

Scores

VersionScoreVectorScored by
CVSS 3.1MEDIUM 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HNVD · nvd@nist.gov (Primary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linuxaffected df6fb868d6118686805c2fa566e213a8f31c8e4f < 7f3e5d72455936f42709116fabeca3bb216cda62 ; affected df6fb868d6118686805c2fa566e213a8f31c8e4f < 21d8efda029948d3666b0db5afcc0d36c0984aae ; affected df6fb868d6118686805c2fa566e213a8f31c8e4f < fc961dd7272b5e4a462999635e44a4770d7f2482 ; affected df6fb868d6118686805c2fa566e213a8f31c8e4f < a8365d1064ded323797c5e28e91070c52f44b76c ; affected df6fb868d6118686805c2fa566e213a8f31c8e4f < a2f6ff3444b663d6cfa63eadd61327a18592885a ; affected df6fb868d6118686805c2fa566e213a8f31c8e4f < c9f6c51d36482805ac3ffadb9663fe775a13e926
Linux · Linuxaffected 2.6.24 ; unaffected 0 < 2.6.24 ; unaffected 5.10.253 ≤ 5.10.* ; unaffected 5.15.203 ≤ 5.15.* ; unaffected 6.1.168 ≤ 6.1.* ; unaffected 6.6.131 ≤ 6.6.*

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD