CVE-2026-31577 | Linux Kernel up to 6.12.82/6.18.23/6.19.13/7.0.0 nilfs_mdt_save_to_shadow_map null pointer dereference

VDB-359382 · CVE-2026-31577 · GCVE-0-2026-31577 LINUX KERNEL UP TO 6.12.82/6.18.23/6.19.13/7.0.0 NILFS_MDT_SAVE_TO_SHADOW_MAP NULL POINTER DEREFERENCE HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 5.5 $0-$5k 0.86+ Summaryinfo A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.12.82/6.18.23/6.19.13/7.0.0. Affected by this issue is the function nilfs_mdt_save_to_shadow_map. The manipulation results in null pointer dereference. This vulnerability is reported as CVE-2026-31577. No exploit exists. You should upgrade the affected component. Detailsinfo A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.12.82/6.18.23/6.19.13/7.0.0. Affected is the function nilfs_mdt_save_to_shadow_map. 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: nilfs2: fix NULL i_assoc_inode dereference in nilfs_mdt_save_to_shadow_map The DAT inode's btree node cache (i_assoc_inode) is initialized lazily during btree operations. However, nilfs_mdt_save_to_shadow_map() assumes i_assoc_inode is already initialized when copying dirty pages to the shadow map during GC. If NILFS_IOCTL_CLEAN_SEGMENTS is called immediately after mount before any btree operation has occurred on the DAT inode, i_assoc_inode is NULL leading to a general protection fault. Fix this by calling nilfs_attach_btree_node_cache() on the DAT inode in nilfs_dat_read() at mount time, ensuring i_assoc_inode is always initialized before any GC operation can use it. The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2026-31577 since 03/09/2026. Technical details are known, but there is no available exploit. Upgrading to version 6.12.83, 6.18.24, 6.19.14 or 7.0.1 eliminates this vulnerability. Applying the patch 449ec5fc99f45974525ba9eea16b6670c45cd363/c36e206f302f1ddefed92d09ecbba070e1ae079e/41de342278ae025c99cc8d33648773f05e306cf1/97fb7afec404912d967a7d4715f37742666b3084 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 6.12.0 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 6.12.81 6.12.82 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 6.18.22 6.18.23 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 6.19.12 6.19.13 7.0 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: 5.7 VulDB Meta Temp Score: 5.5 VulDB Base Score: 5.7 VulDB Temp Score: 5.5 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 6.12.83/6.18.24/6.19.14/7.0.1 Patch: 449ec5fc99f45974525ba9eea16b6670c45cd363/c36e206f302f1ddefed92d09ecbba070e1ae079e/41de342278ae025c99cc8d33648773f05e306cf1/97fb7afec404912d967a7d4715f37742666b3084 Timelineinfo 03/09/2026 CVE reserved 04/24/2026 +45 days Advisory disclosed 04/24/2026 +0 days VulDB entry created 04/24/2026 +0 days VulDB entry last update Sourcesinfo Vendor: kernel.org Advisory: git.kernel.org Status: Confirmed CVE: CVE-2026-31577 (🔒) GCVE (CVE): GCVE-0-2026-31577 GCVE (VulDB): GCVE-100-359382 Entryinfo Created: 04/24/2026 17:48 Changes: 04/24/2026 17:48 (58) Complete: 🔍 Cache ID: 99:188:101 Discussion No comments yet. 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