{"id":"CVE-2026-72347","title":"netfilter: xt_connmark: reject invalid shift parameters","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: xt_connmark: reject invalid shift parameters\n\nRevision 2 of the CONNMARK target accepts user-controlled shift\nparameters and applies them to 32-bit mark valu…","severity":"high","cvss":7.3,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 472a73e00757b971d613d796374d2727b2e4954d < d8ce63d928b457fba7ed1e302492dfd32293671c","Linux >= 472a73e00757b971d613d796374d2727b2e4954d < 9657bb11a6376ab0a79f05d433713d6944111e9d","Linux >= 472a73e00757b971d613d796374d2727b2e4954d < 8ace320ac4416f5e5fbcd065309fb2dfcce787b0","Linux >= 472a73e00757b971d613d796374d2727b2e4954d < c3fa852d117b3fda72265e4230e3967db4a74fcf","Linux >= 472a73e00757b971d613d796374d2727b2e4954d < 4eef84b09a3836919360c4232b0f16651a155eec","Linux >= 472a73e00757b971d613d796374d2727b2e4954d < 230173cc6105bdfb2696d37e6e56687b003fbe63","Linux >= 472a73e00757b971d613d796374d2727b2e4954d < 1b47026fb4b35bac850ad6e8a4ad7fc018e09ebc","Linux 4.17"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-16T18:47:35.760331Z"},"published":"2026-08-15","updated":"2026-10-16","sourceUpdated":"2026-10-16T18:55:19.565Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-72347","references":[{"url":"https://git.kernel.org/stable/c/d8ce63d928b457fba7ed1e302492dfd32293671c"},{"url":"https://git.kernel.org/stable/c/9657bb11a6376ab0a79f05d433713d6944111e9d"},{"url":"https://git.kernel.org/stable/c/8ace320ac4416f5e5fbcd065309fb2dfcce787b0"},{"url":"https://git.kernel.org/stable/c/c3fa852d117b3fda72265e4230e3967db4a74fcf"},{"url":"https://git.kernel.org/stable/c/4eef84b09a3836919360c4232b0f16651a155eec"},{"url":"https://git.kernel.org/stable/c/230173cc6105bdfb2696d37e6e56687b003fbe63"},{"url":"https://git.kernel.org/stable/c/1b47026fb4b35bac850ad6e8a4ad7fc018e09ebc"}],"tags":["cve.org"],"epss":0.00174,"epssPercentile":0.0638,"ingestedAt":"2026-10-16T19:46:24.404Z","slug":"CVE-2026-72347","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: xt_connmark: reject invalid shift parameters\n\nRevision 2 of the CONNMARK target accepts user-controlled shift\nparameters and applies them to 32-bit mark values in\nconnmark_tg_shift().\n\nA shift_bits value of 32 or more triggers an undefined-shift bug when\nthe rule is evaluated. Invalid shift_dir values are also accepted and\nsilently fall back to the left-shift path.\n\nReject invalid revision-2 shift parameters in connmark_tg_check() so\nmalformed rules fail at installation time, before they can reach the\npacket path.\n\n## Affected\n\n- `Linux >= 472a73e00757b971d613d796374d2727b2e4954d < d8ce63d928b457fba7ed1e302492dfd32293671c`\n- `Linux >= 472a73e00757b971d613d796374d2727b2e4954d < 9657bb11a6376ab0a79f05d433713d6944111e9d`\n- `Linux >= 472a73e00757b971d613d796374d2727b2e4954d < 8ace320ac4416f5e5fbcd065309fb2dfcce787b0`\n- `Linux >= 472a73e00757b971d613d796374d2727b2e4954d < c3fa852d117b3fda72265e4230e3967db4a74fcf`\n- `Linux >= 472a73e00757b971d613d796374d2727b2e4954d < 4eef84b09a3836919360c4232b0f16651a155eec`\n- `Linux >= 472a73e00757b971d613d796374d2727b2e4954d < 230173cc6105bdfb2696d37e6e56687b003fbe63`\n- `Linux >= 472a73e00757b971d613d796374d2727b2e4954d < 1b47026fb4b35bac850ad6e8a4ad7fc018e09ebc`\n- `Linux 4.17`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":40,"depthScoreParts":{"impact":40.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}