{"id":"CVE-2026-23437","title":"net: shaper: protect late read accesses to the hierarchy","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: shaper: protect late read accesses to the hierarchy\n\nWe look up a netdev during prep of Netlink ops (pre- callbacks)\nand take a ref to it. Then later in the body o…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 4b623f9f0f59652ea71fcb27d60b4c3b65126dbb < 581eee0890a8bde44f1fb78ad3e70502a897d583","Linux >= 4b623f9f0f59652ea71fcb27d60b4c3b65126dbb < 348758ba74e6a348299965b16a97cfb817545cc0","Linux >= 4b623f9f0f59652ea71fcb27d60b4c3b65126dbb < 0f9ea7141f365b4f27226898e62220fb98ef8dc6","Linux 6.13"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T15:08:04.357382Z"},"published":"2026-04-03","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:09:56.099Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-23437","references":[{"url":"https://git.kernel.org/stable/c/581eee0890a8bde44f1fb78ad3e70502a897d583"},{"url":"https://git.kernel.org/stable/c/348758ba74e6a348299965b16a97cfb817545cc0"},{"url":"https://git.kernel.org/stable/c/0f9ea7141f365b4f27226898e62220fb98ef8dc6"}],"tags":["cve.org"],"epss":0.00127,"epssPercentile":0.02133,"ingestedAt":"2026-10-16T17:24:46.646Z","slug":"CVE-2026-23437","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet: shaper: protect late read accesses to the hierarchy\n\nWe look up a netdev during prep of Netlink ops (pre- callbacks)\nand take a ref to it. Then later in the body of the callback\nwe take its lock or RCU which are the actual protections.\n\nThis is not proper, a conversion from a ref to a locked netdev\nmust include a liveness check (a check if the netdev hasn't been\nunregistered already). Fix the read cases (those under RCU).\nWrites needs a separate change to protect from creating the\nhierarchy after flush has already run.\n\n## Affected\n\n- `Linux >= 4b623f9f0f59652ea71fcb27d60b4c3b65126dbb < 581eee0890a8bde44f1fb78ad3e70502a897d583`\n- `Linux >= 4b623f9f0f59652ea71fcb27d60b4c3b65126dbb < 348758ba74e6a348299965b16a97cfb817545cc0`\n- `Linux >= 4b623f9f0f59652ea71fcb27d60b4c3b65126dbb < 0f9ea7141f365b4f27226898e62220fb98ef8dc6`\n- `Linux 6.13`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}