CVE-2026-31422 | Linux Kernel up to 6.1.167/6.6.133/6.12.80/6.18.21/6.19.11 flow_change null pointer dereference

VDB-357150 · CVE-2026-31422 · GCVE-0-2026-31422 LINUX KERNEL UP TO 6.1.167/6.6.133/6.12.80/6.18.21/6.19.11 FLOW_CHANGE NULL POINTER DEREFERENCE HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 4.6 $0-$5k 3.01+ Summaryinfo A vulnerability labeled as critical has been found in Linux Kernel up to 6.1.167/6.6.133/6.12.80/6.18.21/6.19.11. This affects the function flow_change. The manipulation results in null pointer dereference. This vulnerability is known as CVE-2026-31422. No exploit is available. The affected component should be upgraded. Detailsinfo A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.1.167/6.6.133/6.12.80/6.18.21/6.19.11. Affected is the function flow_change. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. CVE summarizes: In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_flow: fix NULL pointer dereference on shared blocks flow_change() calls tcf_block_q() and dereferences q->handle to derive a default baseclass. Shared blocks leave block->q NULL, causing a NULL deref when a flow filter without a fully qualified baseclass is created on a shared block. Check tcf_block_shared() before accessing block->q and return -EINVAL for shared blocks. This avoids the null-deref shown below: ======================================================================= KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] RIP: 0010:flow_change (net/sched/cls_flow.c:508) Call Trace: tc_new_tfilter (net/sched/cls_api.c:2432) rtnetlink_rcv_msg (net/core/rtnetlink.c:6980) [...] ======================================================================= The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2026-31422 since 03/09/2026. The exploitability is told to be difficult. Technical details are known, but there is no available exploit. Upgrading to version 6.1.168, 6.6.134, 6.12.81, 6.18.22 or 6.19.12 eliminates this vulnerability. Applying the patch cc707a4fd4c3b6ab2722e06bc359aa010e13d408/4a09f72007201c9f667dc47f64517ec23eea65e5/9bf5fc36a43f7b8b5507c96e74fb81f1e8b4957e/a208c3e1232997e9317887294c20008dfcb75449/415ea0c973c754b9f375225807810eb9045f4293/1a280dd4bd1d616a01d6ffe0de284c907b555504 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. Productinfo Type Operating System Vendor Linux Name Kernel Version 6.1.167 6.6.133 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 6.12.80 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 6.18.21 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 6.19.11 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: 4.8 VulDB Meta Temp Score: 4.6 VulDB Base Score: 4.8 VulDB Temp Score: 4.6 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: Null pointer dereference CWE: CWE-476 / CWE-404 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 6.1.168/6.6.134/6.12.81/6.18.22/6.19.12 Patch: cc707a4fd4c3b6ab2722e06bc359aa010e13d408/4a09f72007201c9f667dc47f64517ec23eea65e5/9bf5fc36a43f7b8b5507c96e74fb81f1e8b4957e/a208c3e1232997e9317887294c20008dfcb75449/415ea0c973c754b9f375225807810eb9045f4293/1a280dd4bd1d616a01d6ffe0de284c907b555504 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-2026-31422 (🔒) GCVE (CVE): GCVE-0-2026-31422 GCVE (VulDB): GCVE-100-357150 Entryinfo Created: 04/13/2026 16:03 Changes: 04/13/2026 16:03 (58) Complete: 🔍 Cache ID: 99:44F:101 Discussion No comments yet. 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