CVE-2026-31428netfilter: nfnetlink_log: fix uninitialized padding leak in NFULA_PAYLOAD
- 5.5MediumCVSS base score
- 0.14%Exploitation in 30 daysEPSS · top 97% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By Linux
- 35 days later
· 35 days later
Published
- 7 months later
· 7 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.14% · top 97% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Affected products
- affected df6fb868d6118686805c2fa566e213a8f31c8e4f – < 7f3e5d72455936f42709116fabeca3bb216cda62
- affected df6fb868d6118686805c2fa566e213a8f31c8e4f – < 21d8efda029948d3666b0db5afcc0d36c0984aae
- affected df6fb868d6118686805c2fa566e213a8f31c8e4f – < fc961dd7272b5e4a462999635e44a4770d7f2482
- affected df6fb868d6118686805c2fa566e213a8f31c8e4f – < a8365d1064ded323797c5e28e91070c52f44b76c
- affected df6fb868d6118686805c2fa566e213a8f31c8e4f – < a2f6ff3444b663d6cfa63eadd61327a18592885a
- affected df6fb868d6118686805c2fa566e213a8f31c8e4f – < c9f6c51d36482805ac3ffadb9663fe775a13e926
- affected df6fb868d6118686805c2fa566e213a8f31c8e4f – < 7eff72968161fb8ddb26113344de3b92fb7d7ef5
- affected df6fb868d6118686805c2fa566e213a8f31c8e4f – < 52025ebaa29f4eb4ed8bf92ce83a68f24ab7fdf7
- affected 2.6.24
- unaffected < 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.*
- unaffected 6.12.80 – ≤ 6.12.*
- unaffected 6.18.21 – ≤ 6.18.*
- unaffected 6.19.11 – ≤ 6.19.*
- unaffected 7.0 – ≤ *
References
References11
- https://git.kernel.org/stable/c/7f3e5d72455936f42709116fabeca3bb216cda62 (opens in a new tab)
- https://git.kernel.org/stable/c/21d8efda029948d3666b0db5afcc0d36c0984aae (opens in a new tab)
- https://git.kernel.org/stable/c/fc961dd7272b5e4a462999635e44a4770d7f2482 (opens in a new tab)
- https://git.kernel.org/stable/c/a8365d1064ded323797c5e28e91070c52f44b76c (opens in a new tab)
- https://git.kernel.org/stable/c/a2f6ff3444b663d6cfa63eadd61327a18592885a (opens in a new tab)
- https://git.kernel.org/stable/c/c9f6c51d36482805ac3ffadb9663fe775a13e926 (opens in a new tab)
- https://git.kernel.org/stable/c/7eff72968161fb8ddb26113344de3b92fb7d7ef5 (opens in a new tab)
- https://git.kernel.org/stable/c/52025ebaa29f4eb4ed8bf92ce83a68f24ab7fdf7 (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-21957 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-31428)Record last updated .