CVE-2026-53271

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-53271", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-06-09T07:44:35.395Z", "datePublished": "2026-06-25T08:39:56.489Z", "dateUpdated": "2026-06-25T08:39:56.489Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-06-25T08:39:56.489Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix NULL-deref of opinfo->conn in oplock/lease break notifiers\n\nsmb2_oplock_break_noti() and smb2_lease_break_noti() read opinfo->conn\ninto a local with neither READ_ONCE() nor a NULL check. Both run from\noplock_break() after opinfo_get_list() has dropped ci->m_lock, so a\nconcurrent SMB2 LOGOFF (session_fd_check()) can set op->conn = NULL\nunder ci->m_lock within that window. ksmbd_conn_r_count_inc(conn) then\nwrites through NULL at offset 0xc4 -- a remotely triggerable oops.\n\nGuard both reads the way compare_guid_key() already does: read\nopinfo->conn with READ_ONCE() and return early if it is NULL, before\nallocating the work struct so nothing leaks. A NULL conn means the\nclient is gone and the break is moot, so return 0; oplock_break() treats\nthat as success and runs the normal teardown."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/smb/server/oplock.c"], "versions": [{"version": "8df4bcdb0a4232192b2445256c39b787d58ef14d", "lessThan": "945a86b21b40fb17183f5b27461baa6f03e2467f", "status": "affected", "versionType": "git"}, {"version": "c8efcc786146a951091588e5fa7e3c754850cb3c", "lessThan": "1ff58dcfcab434ebb51649da33774fbb8e1f7b67", "status": "affected", "versionType": "git"}, {"version": "c8efcc786146a951091588e5fa7e3c754850cb3c", "lessThan": "e735dbd489e3ea02be78dba991056fe1138be51e", "status": "affected", "versionType": "git"}, {"version": "c8efcc786146a951091588e5fa7e3c754850cb3c", "lessThan": "75e33deda658c1ab3a9336cbdb1436536f9b3660", "status": "affected", "versionType": "git"}, {"version": "c8efcc786146a951091588e5fa7e3c754850cb3c", "lessThan": "b003086d76968298f22e7cf62239833b5a3a06b1", "status": "affected", "versionType": "git"}, {"version": "6.6.32", "lessThan": "6.6.143", "status": "affected", "versionType": "semver"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/smb/server/oplock.c"], "versions": [{"version": "6.9", "status": "affected"}, {"version": "0", "lessThan": "6.9", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.143", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.94", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.36", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0.13", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.32", "versionEndExcluding": "6.6.143"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.12.94"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.18.36"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "7.0.13"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "7.1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/945a86b21b40fb17183f5b27461baa6f03e2467f"}, {"url": "https://git.kernel.org/stable/c/1ff58dcfcab434ebb51649da33774fbb8e1f7b67"}, {"url": "https://git.kernel.org/stable/c/e735dbd489e3ea02be78dba991056fe1138be51e"}, {"url": "https://git.kernel.org/stable/c/75e33deda658c1ab3a9336cbdb1436536f9b3660"}, {"url": "https://git.kernel.org/stable/c/b003086d76968298f22e7cf62239833b5a3a06b1"}], "title": "ksmbd: fix NULL-deref of opinfo->conn in oplock/lease break notifiers", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/smb/server/oplock.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "945a86b21b40fb17183f5b27461baa6f03e2467f", "status": "affected", "version": "8df4bcdb0a4232192b2445256c39b787d58ef14d", "versionType": "git"}, {"lessThan": "1ff58dcfcab434ebb51649da33774fbb8e1f7b67", "status": "affected", "version": "c8efcc786146a951091588e5fa7e3c754850cb3c", "versionType": "git"}, {"lessThan": "e735dbd489e3ea02be78dba991056fe1138be51e", "status": "affected", "version": "c8efcc786146a951091588e5fa7e3c754850cb3c", "versionType": "git"}, {"lessThan": "75e33deda658c1ab3a9336cbdb1436536f9b3660", "status": "affected", "version": "c8efcc786146a951091588e5fa7e3c754850cb3c", "versionType": "git"}, {"lessThan": "b003086d76968298f22e7cf62239833b5a3a06b1", "status": "affected", "version": "c8efcc786146a951091588e5fa7e3c754850cb3c", "versionType": "git"}, {"lessThan": "6.6.143", "status": "affected", "version": "6.6.32", "versionType": "semver"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/smb/server/oplock.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.9"}, {"lessThan": "6.9", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.143", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.94", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.36", "versionType": "semver"}, {"lessThanOrEqual": "7.0.*", "status": "unaffected", "version": "7.0.13", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.1", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "4870AAED-882B-41F6-9339-0744EE085A78", "versionEndExcluding": "6.6.143", "versionStartIncluding": "6.6.32", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "0FA23C34-76C0-4758-A17E-44FD25C1DEA5", "versionEndExcluding": "6.12.94", "versionStartIncluding": "6.9", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "389025D2-958D-41BD-BD96-70ED1033A9F3", "versionEndExcluding": "6.18.36", "versionStartIncluding": "6.13", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "6A64BF9F-3BCA-42FD-98CB-8F03474D2B1E", "versionEndExcluding": "7.0.13", "versionStartIncluding": "6.19", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*", "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*", "matchCriteriaId": "0D38F0BF-A728-4133-A358-D44A2F7EE6D6", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*", "matchCriteriaId": "EC732D08-5F7B-46D9-B154-E60C7F4F0A97", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*", "matchCriteriaId": "E5910A9D-F60A-409A-B486-FE66BFEBA9B9", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:*", "matchCriteriaId": "81DFF19E-9CF8-49C6-8C36-1E4038622933", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc6:*:*:*:*:*:*", "matchCriteriaId": "B0E8FC71-3952-444C-83E9-718DBBBEC615", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix NULL-deref of opinfo->conn in oplock/lease break notifiers\n\nsmb2_oplock_break_noti() and smb2_lease_break_noti() read opinfo->conn\ninto a local with neither READ_ONCE() nor a NULL check. Both run from\noplock_break() after opinfo_get_list() has dropped ci->m_lock, so a\nconcurrent SMB2 LOGOFF (session_fd_check()) can set op->conn = NULL\nunder ci->m_lock within that window. ksmbd_conn_r_count_inc(conn) then\nwrites through NULL at offset 0xc4 -- a remotely triggerable oops.\n\nGuard both reads the way compare_guid_key() already does: read\nopinfo->conn with READ_ONCE() and return early if it is NULL, before\nallocating the work struct so nothing leaks. A NULL conn means the\nclient is gone and the break is moot, so return 0; oplock_break() treats\nthat as success and runs the normal teardown."}], "id": "CVE-2026-53271", "lastModified": "2026-07-08T04:01:39.257", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 5.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2026-06-25T09:16:45.247", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/1ff58dcfcab434ebb51649da33774fbb8e1f7b67"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/75e33deda658c1ab3a9336cbdb1436536f9b3660"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/945a86b21b40fb17183f5b27461baa6f03e2467f"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/b003086d76968298f22e7cf62239833b5a3a06b1"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/e735dbd489e3ea02be78dba991056fe1138be51e"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-476"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: ksmbd: fix NULL-deref of opinfo->conn in oplock/lease break notifiers", "id": "2492712", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2492712"}, "csaw": false, "cwe": "CWE-476", "details": ["A flaw was found in the ksmbd component of the Linux kernel. A remote attacker could exploit a NULL-dereference vulnerability in the oplock/lease break notifiers. This occurs because `opinfo->conn` is read without proper checks, allowing a concurrent Server Message Block (SMB2) LOGOFF to set `op->conn` to NULL. Successful exploitation leads to a kernel oops, resulting in a Denial of Service (DoS)."], "name": "CVE-2026-53271", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-06-25T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-53271\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-53271\nhttps://lore.kernel.org/linux-cve-announce/2026062518-CVE-2026-53271-711f@gregkh/T"]}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[8df4bcdb0a4232192b2445256c39b787d58ef14d,945a86b21b40fb17183f5b27461baa6f03e2467f)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c8efcc786146a951091588e5fa7e3c754850cb3c,1ff58dcfcab434ebb51649da33774fbb8e1f7b67)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c8efcc786146a951091588e5fa7e3c754850cb3c,e735dbd489e3ea02be78dba991056fe1138be51e)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c8efcc786146a951091588e5fa7e3c754850cb3c,75e33deda658c1ab3a9336cbdb1436536f9b3660)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c8efcc786146a951091588e5fa7e3c754850cb3c,b003086d76968298f22e7cf62239833b5a3a06b1)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.6.32,6.6.143)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "6.9"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,6.9)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.143,7.0.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.94,7.0.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.36,7.0.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.0.13,8.0.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-06-25T12:15:03.844681+00:00", "updated": "2026-08-13T15:15:13.215506+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}