CVE-2026-23456 | Linux Kernel up to 7.0-rc4 nf_conntrack_h323 decode_int out-of-bounds

VDB-355155 · CVE-2026-23456 · GCVE-0-2026-23456 LINUX KERNEL UP TO 7.0-RC4 NF_CONNTRACK_H323 DECODE_INT OUT-OF-BOUNDS HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 3.4 $0-$5k 0.56 Summaryinfo A vulnerability has been found in Linux Kernel up to 7.0-rc4 and classified as critical. This impacts the function decode_int of the component nf_conntrack_h323. Performing a manipulation results in out-of-bounds. This vulnerability is known as CVE-2026-23456. No exploit is available. The affected component should be upgraded. Detailsinfo A vulnerability was found in Linux Kernel up to 7.0-rc4. It has been classified as problematic. This affects the function decode_int of the component nf_conntrack_h323. The manipulation with an unknown input leads to a out-of-bounds vulnerability. CWE is classifying the issue as CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality. The summary by CVE is: In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_h323: fix OOB read in decode_int() CONS case In decode_int(), the CONS case calls get_bits(bs, 2) to read a length value, then calls get_uint(bs, len) without checking that len bytes remain in the buffer. The existing boundary check only validates the 2 bits for get_bits(), not the subsequent 1-4 bytes that get_uint() reads. This allows a malformed H.323/RAS packet to cause a 1-4 byte slab-out-of-bounds read. Add a boundary check for len bytes after get_bits() and before get_uint(). It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-23456 since 01/13/2026. 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 04/03/2026). Upgrading to version 6.1.167, 6.6.130, 6.12.78, 6.18.20, 6.19.10 or 7.0-rc5 eliminates this vulnerability. Applying the patch 41b417ff73a24b2c68134992cc44c88db27f482d/52235bf88159a1ef16434ab49e47e99c8a09ab20/774a434f8c9c8602a976b2536f65d0172a07f4d2/6bce72daeccca9aa1746e92d6c3d4784e71f2ebb/fb6c3596823ec5dd09c2123340330d7448f51a59/1e3a3593162c96e8a8de48b1e14f60c3b57fca8a 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 6.1.166 6.6.129 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 6.18.0 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 6.19.0 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 7.0-rc1 7.0-rc2 7.0-rc3 7.0-rc4 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: 3.5 VulDB Meta Temp Score: 3.4 VulDB Base Score: 3.5 VulDB Temp Score: 3.4 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: Out-of-bounds CWE: CWE-125 / CWE-119 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 6.1.167/6.6.130/6.12.78/6.18.20/6.19.10/7.0-rc5 Patch: 41b417ff73a24b2c68134992cc44c88db27f482d/52235bf88159a1ef16434ab49e47e99c8a09ab20/774a434f8c9c8602a976b2536f65d0172a07f4d2/6bce72daeccca9aa1746e92d6c3d4784e71f2ebb/fb6c3596823ec5dd09c2123340330d7448f51a59/1e3a3593162c96e8a8de48b1e14f60c3b57fca8a Timelineinfo 01/13/2026 CVE reserved 04/03/2026 +79 days Advisory disclosed 04/03/2026 +0 days VulDB entry created 04/03/2026 +0 days VulDB entry last update Sourcesinfo Vendor: kernel.org Advisory: git.kernel.org Status: Confirmed CVE: CVE-2026-23456 (🔒) GCVE (CVE): GCVE-0-2026-23456 GCVE (VulDB): GCVE-100-355155 Entryinfo Created: 04/03/2026 18:15 Changes: 04/03/2026 18:15 (59) Complete: 🔍 Cache ID: 99:E70:101 Discussion No comments yet. 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