{"api_version":"1","generated_at":"2026-07-24T17:18:00+00:00","cve":"CVE-2026-63802","urls":{"html":"https://cve.report/CVE-2026-63802","api":"https://cve.report/api/cve/CVE-2026-63802.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-63802","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-63802"},"summary":{"title":"blk-cgroup: fix UAF in __blkcg_rstat_flush()","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.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-19 12:16:52","updated_at":"2026-07-20 15:16:47"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","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","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","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","data":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/96e545410c4f74c89d496c1d5d9ef8d08f14368b","name":"https://git.kernel.org/stable/c/96e545410c4f74c89d496c1d5d9ef8d08f14368b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/afebe44facc48a61761e885bbb7f0380d4a603ec","name":"https://git.kernel.org/stable/c/afebe44facc48a61761e885bbb7f0380d4a603ec","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/bbebd9425cad3573d1527441753899b926525a0f","name":"https://git.kernel.org/stable/c/bbebd9425cad3573d1527441753899b926525a0f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/5e5b7f2ef854936e95dceb6a2fdfefcb7152d2c6","name":"https://git.kernel.org/stable/c/5e5b7f2ef854936e95dceb6a2fdfefcb7152d2c6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/0ab5ee5a1badb58cbb2242617cb01a4972b1f2a2","name":"https://git.kernel.org/stable/c/0ab5ee5a1badb58cbb2242617cb01a4972b1f2a2","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-63802","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63802","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 20cb1c2fb7568a6054c55defe044311397e01ddb 96e545410c4f74c89d496c1d5d9ef8d08f14368b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 20cb1c2fb7568a6054c55defe044311397e01ddb bbebd9425cad3573d1527441753899b926525a0f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 20cb1c2fb7568a6054c55defe044311397e01ddb 5e5b7f2ef854936e95dceb6a2fdfefcb7152d2c6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 20cb1c2fb7568a6054c55defe044311397e01ddb afebe44facc48a61761e885bbb7f0380d4a603ec git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 20cb1c2fb7568a6054c55defe044311397e01ddb 0ab5ee5a1badb58cbb2242617cb01a4972b1f2a2 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 0f6090d90f627d8c58f939067d6c6821ce1b3c68 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.3.9 6.4 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.4","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.4 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.144 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.95 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.38 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.3 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"63802","cve":"CVE-2026-63802","epss":"0.001680000","percentile":"0.063820000","score_date":"2026-07-20","updated_at":"2026-07-21 00:13:14"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["block/blk-cgroup.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"96e545410c4f74c89d496c1d5d9ef8d08f14368b","status":"affected","version":"20cb1c2fb7568a6054c55defe044311397e01ddb","versionType":"git"},{"lessThan":"bbebd9425cad3573d1527441753899b926525a0f","status":"affected","version":"20cb1c2fb7568a6054c55defe044311397e01ddb","versionType":"git"},{"lessThan":"5e5b7f2ef854936e95dceb6a2fdfefcb7152d2c6","status":"affected","version":"20cb1c2fb7568a6054c55defe044311397e01ddb","versionType":"git"},{"lessThan":"afebe44facc48a61761e885bbb7f0380d4a603ec","status":"affected","version":"20cb1c2fb7568a6054c55defe044311397e01ddb","versionType":"git"},{"lessThan":"0ab5ee5a1badb58cbb2242617cb01a4972b1f2a2","status":"affected","version":"20cb1c2fb7568a6054c55defe044311397e01ddb","versionType":"git"},{"status":"affected","version":"0f6090d90f627d8c58f939067d6c6821ce1b3c68","versionType":"git"},{"lessThan":"6.4","status":"affected","version":"6.3.9","versionType":"semver"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["block/blk-cgroup.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.4"},{"lessThan":"6.4","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.144","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.95","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.38","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.3","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.144","versionStartIncluding":"6.4","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.95","versionStartIncluding":"6.4","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.38","versionStartIncluding":"6.4","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.3","versionStartIncluding":"6.4","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc1","versionStartIncluding":"6.4","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.3.9","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"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."}],"metrics":[{"cvssV3_1":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"providerMetadata":{"dateUpdated":"2026-07-20T13:40:12.508Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/96e545410c4f74c89d496c1d5d9ef8d08f14368b"},{"url":"https://git.kernel.org/stable/c/bbebd9425cad3573d1527441753899b926525a0f"},{"url":"https://git.kernel.org/stable/c/5e5b7f2ef854936e95dceb6a2fdfefcb7152d2c6"},{"url":"https://git.kernel.org/stable/c/afebe44facc48a61761e885bbb7f0380d4a603ec"},{"url":"https://git.kernel.org/stable/c/0ab5ee5a1badb58cbb2242617cb01a4972b1f2a2"}],"title":"blk-cgroup: fix UAF in __blkcg_rstat_flush()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-63802","datePublished":"2026-07-19T12:02:08.020Z","dateReserved":"2026-07-19T07:54:57.013Z","dateUpdated":"2026-07-20T13:40:12.508Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-19 12:16:52","lastModifiedDate":"2026-07-20 15:16:47","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"63802","Ordinal":"1","Title":"blk-cgroup: fix UAF in __blkcg_rstat_flush()","CVE":"CVE-2026-63802","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"63802","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"blk-cgroup: fix UAF in __blkcg_rstat_flush()"}]}}}