{"api_version":"1","generated_at":"2026-05-11T11:02:40+00:00","cve":"CVE-2026-43376","urls":{"html":"https://cve.report/CVE-2026-43376","api":"https://cve.report/api/cve/CVE-2026-43376.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-43376","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-43376"},"summary":{"title":"ksmbd: fix use-after-free by using call_rcu() for oplock_info","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free by using call_rcu() for oplock_info\n\nksmbd currently frees oplock_info immediately using kfree(), even\nthough it is accessed under RCU read-side critical sections in places\nlike opinfo_get() and proc_show_files().\n\nSince there is no RCU grace period delay between nullifying the pointer\nand freeing the memory, a reader can still access oplock_info\nstructure after it has been freed. This can leads to a use-after-free\nespecially in opinfo_get() where atomic_inc_not_zero() is called on\nalready freed memory.\n\nFix this by switching to deferred freeing using call_rcu().","state":"PUBLISHED","assigner":"Linux","published_at":"2026-05-08 15:16:48","updated_at":"2026-05-11 08:16:12"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"9.8","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"9.8","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":9.8,"baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/302fef75512b2c8329a3f5efab1ae7ba2562387a","name":"https://git.kernel.org/stable/c/302fef75512b2c8329a3f5efab1ae7ba2562387a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/1dfd062caa165ec9d7ee0823087930f3ab8a6294","name":"https://git.kernel.org/stable/c/1dfd062caa165ec9d7ee0823087930f3ab8a6294","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/08aa9f3c8cf4d0bee44df540dfe34e8d64069f2c","name":"https://git.kernel.org/stable/c/08aa9f3c8cf4d0bee44df540dfe34e8d64069f2c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/1d6abf145615dbfe267ce3b0a271f95e3780e18e","name":"https://git.kernel.org/stable/c/1d6abf145615dbfe267ce3b0a271f95e3780e18e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ce8507ee82c888126d8e7565e27c016308d24cde","name":"https://git.kernel.org/stable/c/ce8507ee82c888126d8e7565e27c016308d24cde","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-43376","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43376","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 296cb5457cc6f4a754c4ae29855f8a253d52bcc6 302fef75512b2c8329a3f5efab1ae7ba2562387a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d54ab1520d43e95f9b2e22d7a05fc9614192e5a5 08aa9f3c8cf4d0bee44df540dfe34e8d64069f2c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 18b4fac5ef17f77fed9417d22210ceafd6525fc7 1d6abf145615dbfe267ce3b0a271f95e3780e18e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 18b4fac5ef17f77fed9417d22210ceafd6525fc7 ce8507ee82c888126d8e7565e27c016308d24cde git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"43376","cve":"CVE-2026-43376","epss":"0.000180000","percentile":"0.049330000","score_date":"2026-05-10","updated_at":"2026-05-11 00:14:41"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/smb/server/oplock.c","fs/smb/server/oplock.h"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"302fef75512b2c8329a3f5efab1ae7ba2562387a","status":"affected","version":"296cb5457cc6f4a754c4ae29855f8a253d52bcc6","versionType":"git"},{"lessThan":"08aa9f3c8cf4d0bee44df540dfe34e8d64069f2c","status":"affected","version":"d54ab1520d43e95f9b2e22d7a05fc9614192e5a5","versionType":"git"},{"lessThan":"1d6abf145615dbfe267ce3b0a271f95e3780e18e","status":"affected","version":"18b4fac5ef17f77fed9417d22210ceafd6525fc7","versionType":"git"},{"lessThan":"ce8507ee82c888126d8e7565e27c016308d24cde","status":"affected","version":"18b4fac5ef17f77fed9417d22210ceafd6525fc7","versionType":"git"},{"lessThan":"1dfd062caa165ec9d7ee0823087930f3ab8a6294","status":"affected","version":"18b4fac5ef17f77fed9417d22210ceafd6525fc7","versionType":"git"},{"status":"affected","version":"d73686367ad68534257cd88a36ca3c52cb8b81d8","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/smb/server/oplock.c","fs/smb/server/oplock.h"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.15"},{"lessThan":"6.15","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.130","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.78","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.19","versionType":"semver"},{"lessThanOrEqual":"6.19.*","status":"unaffected","version":"6.19.9","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.0","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.130","versionStartIncluding":"6.6.88","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.78","versionStartIncluding":"6.12.25","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.19","versionStartIncluding":"6.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19.9","versionStartIncluding":"6.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0","versionStartIncluding":"6.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14.4","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free by using call_rcu() for oplock_info\n\nksmbd currently frees oplock_info immediately using kfree(), even\nthough it is accessed under RCU read-side critical sections in places\nlike opinfo_get() and proc_show_files().\n\nSince there is no RCU grace period delay between nullifying the pointer\nand freeing the memory, a reader can still access oplock_info\nstructure after it has been freed. This can leads to a use-after-free\nespecially in opinfo_get() where atomic_inc_not_zero() is called on\nalready freed memory.\n\nFix this by switching to deferred freeing using call_rcu()."}],"metrics":[{"cvssV3_1":{"baseScore":9.8,"baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"providerMetadata":{"dateUpdated":"2026-05-11T06:33:55.017Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/302fef75512b2c8329a3f5efab1ae7ba2562387a"},{"url":"https://git.kernel.org/stable/c/08aa9f3c8cf4d0bee44df540dfe34e8d64069f2c"},{"url":"https://git.kernel.org/stable/c/1d6abf145615dbfe267ce3b0a271f95e3780e18e"},{"url":"https://git.kernel.org/stable/c/ce8507ee82c888126d8e7565e27c016308d24cde"},{"url":"https://git.kernel.org/stable/c/1dfd062caa165ec9d7ee0823087930f3ab8a6294"}],"title":"ksmbd: fix use-after-free by using call_rcu() for oplock_info","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-43376","datePublished":"2026-05-08T14:21:25.854Z","dateReserved":"2026-05-01T14:12:56.006Z","dateUpdated":"2026-05-11T06:33:55.017Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-08 15:16:48","lastModifiedDate":"2026-05-11 08:16:12","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"43376","Ordinal":"1","Title":"ksmbd: fix use-after-free by using call_rcu() for oplock_info","CVE":"CVE-2026-43376","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"43376","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free by using call_rcu() for oplock_info\n\nksmbd currently frees oplock_info immediately using kfree(), even\nthough it is accessed under RCU read-side critical sections in places\nlike opinfo_get() and proc_show_files().\n\nSince there is no RCU grace period delay between nullifying the pointer\nand freeing the memory, a reader can still access oplock_info\nstructure after it has been freed. This can leads to a use-after-free\nespecially in opinfo_get() where atomic_inc_not_zero() is called on\nalready freed memory.\n\nFix this by switching to deferred freeing using call_rcu().","Type":"Description","Title":"ksmbd: fix use-after-free by using call_rcu() for oplock_info"}]}}}