CVE-2026-31428 | Linux Kernel up to 6.1.167/6.6.130/6.12.79/6.18.20/6.19.10 netfilter __build_packet_message uninitialized pointer

VDB-357155 · CVE-2026-31428 · EUVD-2026-21957 LINUX KERNEL UP TO 6.1.167/6.6.130/6.12.79/6.18.20/6.19.10 NETFILTER __BUILD_PACKET_MESSAGE UNINITIALIZED POINTER HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 5.3 $0-$5k 2.63+ Summaryinfo A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.1.167/6.6.130/6.12.79/6.18.20/6.19.10. The impacted element is the function __build_packet_message of the component netfilter. The manipulation leads to uninitialized pointer. This vulnerability is referenced as CVE-2026-31428. No exploit is available. It is advisable to upgrade the affected component. Detailsinfo A vulnerability was found in Linux Kernel up to 6.1.167/6.6.130/6.12.79/6.18.20/6.19.10. It has been rated as critical. This issue affects the function __build_packet_message of the component netfilter. The manipulation with an unknown input leads to a uninitialized pointer vulnerability. Using CWE to declare the problem leads to CWE-824. The product accesses or uses a pointer that has not been initialized. The impact remains unknown. The summary by CVE 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. It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2026-31428 since 03/09/2026. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 04/13/2026). Upgrading to version 6.1.168, 6.6.131, 6.12.80, 6.18.21 or 6.19.11 eliminates this vulnerability. Applying the patch fc961dd7272b5e4a462999635e44a4770d7f2482/a8365d1064ded323797c5e28e91070c52f44b76c/a2f6ff3444b663d6cfa63eadd61327a18592885a/c9f6c51d36482805ac3ffadb9663fe775a13e926/7eff72968161fb8ddb26113344de3b92fb7d7ef5/52025ebaa29f4eb4ed8bf92ce83a68f24ab7fdf7 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version. The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-21957). Productinfo Type Operating System Vendor Linux Name Kernel Version 6.1.167 6.6.130 6.12.0 6.12.1 6.12.2 6.12.3 6.12.4 6.12.5 6.12.6 6.12.7 6.12.8 6.12.9 6.12.10 6.12.11 6.12.12 6.12.13 6.12.14 6.12.15 6.12.16 6.12.17 6.12.18 6.12.19 6.12.20 6.12.21 6.12.22 6.12.23 6.12.24 6.12.25 6.12.26 6.12.27 6.12.28 6.12.29 6.12.30 6.12.31 6.12.32 6.12.33 6.12.34 6.12.35 6.12.36 6.12.37 6.12.38 6.12.39 6.12.40 6.12.41 6.12.42 6.12.43 6.12.44 6.12.45 6.12.46 6.12.47 6.12.48 6.12.49 6.12.50 6.12.51 6.12.52 6.12.53 6.12.54 6.12.55 6.12.56 6.12.57 6.12.58 6.12.59 6.12.60 6.12.61 6.12.62 6.12.63 6.12.64 6.12.65 6.12.66 6.12.67 6.12.68 6.12.69 6.12.70 6.12.71 6.12.72 6.12.73 6.12.74 6.12.75 6.12.76 6.12.77 6.12.78 6.12.79 6.18.0 6.18.1 6.18.2 6.18.3 6.18.4 6.18.5 6.18.6 6.18.7 6.18.8 6.18.9 6.18.10 6.18.11 6.18.12 6.18.13 6.18.14 6.18.15 6.18.16 6.18.17 6.18.18 6.18.19 6.18.20 6.19.0 6.19.1 6.19.2 6.19.3 6.19.4 6.19.5 6.19.6 6.19.7 6.19.8 6.19.9 6.19.10 License open-source Website Vendor: https://www.kernel.org/ CPE 2.3info 🔒 🔒 🔒 CPE 2.2info 🔒 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 5.5 VulDB Meta Temp Score: 5.3 VulDB Base Score: 5.5 VulDB Temp Score: 5.3 VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Uninitialized pointer CWE: CWE-824 / CWE-908 CAPEC: 🔒 ATT&CK: 🔒 Physical: No Local: No Remote: Partially Availability: 🔒 Status: Not defined Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: Upgrade Status: 🔍 0-Day Time: 🔒 Upgrade: Kernel 6.1.168/6.6.131/6.12.80/6.18.21/6.19.11 Patch: fc961dd7272b5e4a462999635e44a4770d7f2482/a8365d1064ded323797c5e28e91070c52f44b76c/a2f6ff3444b663d6cfa63eadd61327a18592885a/c9f6c51d36482805ac3ffadb9663fe775a13e926/7eff72968161fb8ddb26113344de3b92fb7d7ef5/52025ebaa29f4eb4ed8bf92ce83a68f24ab7fdf7 Timelineinfo 03/09/2026 CVE reserved 04/13/2026 +34 days Advisory disclosed 04/13/2026 +0 days VulDB entry created 04/13/2026 +0 days VulDB entry last update Sourcesinfo Vendor: kernel.org Advisory: git.kernel.org Status: Confirmed CVE: CVE-2026-31428 (🔒) GCVE (CVE): GCVE-0-2026-31428 GCVE (VulDB): GCVE-100-357155 EUVD: 🔒 Entryinfo Created: 04/13/2026 16:06 Updated: 04/13/2026 17:58 Changes: 04/13/2026 16:06 (59), 04/13/2026 17:58 (1) Complete: 🔍 Cache ID: 99:744:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸