{"id":"CVE-2026-63802","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-63802","generatedAt":"2026-10-28T04:11:13.592Z","title":"In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: fix UAF in __blkcg_rstat_flush() When multiple blkgs in the same blkcg are released concurrently, a use-after-free can occur.","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nblk-cgroup: fix UAF in __blkcg_rstat_flush()\n\nWhen multiple blkgs in the same blkcg are released concurrently,\na use-after-free can occur. The race happens when one blkg's\n__blkcg_rstat_flush() removes another blkg's iostat entries via\nllist_del_all(). The second blkg sees an empty list and proceeds\nto free itself while the first is still iterating over its entries.\n\nMove the flush from __blkg_release() (RCU callback) to blkg_release()\n(before call_rcu). This ensures the RCU grace period waits for any\nconcurrent flush's rcu_read_lock() section to complete before freeing.","published":"2026-07-19T12:16:53.000Z","lastModified":"2026-10-19T20:19:21.000Z","status":"Modified","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-416","CWE-362"],"affected":["linux/linux kernel"],"epss":{"score":0.00102,"percentile":0.00934,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.10%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/0ab5ee5a1badb58cbb2242617cb01a4972b1f2a2","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5e5b7f2ef854936e95dceb6a2fdfefcb7152d2c6","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/96e545410c4f74c89d496c1d5d9ef8d08f14368b","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/afebe44facc48a61761e885bbb7f0380d4a603ec","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bbebd9425cad3573d1527441753899b926525a0f","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-63802","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}