{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89631", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.738Z", "datePublished": "2026-09-11T19:45:26.444Z", "dateUpdated": "2026-09-11T19:45:26.444Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-09-11T19:45:26.444Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: reject a tree connect response whose byte count is too small\n\nCIFSTCon() bounds its strnlen() over the byte area with the server's\nByteCount minus two, which for ByteCount 0 or 1 goes negative as an int\nand converts to a huge size_t. The later subtraction wraps the __u16\nbytes_left, and that is what bounds cifs_strndup_from_utf16(): a bound of\nup to 65535 against a ~16 KB cifs_req_poolp object runs off the end of the\nslab object, and the bytes reach userspace through tcon->nativeFileSystem\nin /proc/fs/cifs/DebugData.\n\nReject a byte area too small for what the parser consumes. Two bytes is\nthe least it can consume, and no conformant response carries fewer. The\nnew trace point is the 129th smb_eio_trace entry, which __mode(byte)\ncannot represent, so the attribute goes with it."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/smb/client/cifssmb.c", "fs/smb/client/trace.h"], "versions": [{"version": "cc20c031bb067eb3280a1c4b5c42295093e24863", "lessThan": "3be89e8039a85fa3b6cd5f9dcc4c1459eb356c2d", "status": "affected", "versionType": "git"}, {"version": "cc20c031bb067eb3280a1c4b5c42295093e24863", "lessThan": "411e484fe71a7f1028de617447edad9cb6d9d68a", "status": "affected", "versionType": "git"}, {"version": "cc20c031bb067eb3280a1c4b5c42295093e24863", "lessThan": "65deb18359341141d37dc86fc7853511be3c87a7", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/smb/client/cifssmb.c", "fs/smb/client/trace.h"], "versions": [{"version": "2.6.30", "status": "affected"}, {"version": "0", "lessThan": "2.6.30", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.51", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3-rc1", "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": "2.6.30", "versionEndExcluding": "6.18.51"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "7.2.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "7.3-rc1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/3be89e8039a85fa3b6cd5f9dcc4c1459eb356c2d"}, {"url": "https://git.kernel.org/stable/c/411e484fe71a7f1028de617447edad9cb6d9d68a"}, {"url": "https://git.kernel.org/stable/c/65deb18359341141d37dc86fc7853511be3c87a7"}], "title": "smb: client: reject a tree connect response whose byte count is too small", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/smb/client/cifssmb.c", "fs/smb/client/trace.h"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "3be89e8039a85fa3b6cd5f9dcc4c1459eb356c2d", "status": "affected", "version": "cc20c031bb067eb3280a1c4b5c42295093e24863", "versionType": "git"}, {"lessThan": "411e484fe71a7f1028de617447edad9cb6d9d68a", "status": "affected", "version": "cc20c031bb067eb3280a1c4b5c42295093e24863", "versionType": "git"}, {"lessThan": "65deb18359341141d37dc86fc7853511be3c87a7", "status": "affected", "version": "cc20c031bb067eb3280a1c4b5c42295093e24863", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/smb/client/cifssmb.c", "fs/smb/client/trace.h"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "2.6.30"}, {"lessThan": "2.6.30", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.51", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3-rc1", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: reject a tree connect response whose byte count is too small\n\nCIFSTCon() bounds its strnlen() over the byte area with the server's\nByteCount minus two, which for ByteCount 0 or 1 goes negative as an int\nand converts to a huge size_t. The later subtraction wraps the __u16\nbytes_left, and that is what bounds cifs_strndup_from_utf16(): a bound of\nup to 65535 against a ~16 KB cifs_req_poolp object runs off the end of the\nslab object, and the bytes reach userspace through tcon->nativeFileSystem\nin /proc/fs/cifs/DebugData.\n\nReject a byte area too small for what the parser consumes. Two bytes is\nthe least it can consume, and no conformant response carries fewer. The\nnew trace point is the 129th smb_eio_trace entry, which __mode(byte)\ncannot represent, so the attribute goes with it."}], "id": "CVE-2026-89631", "lastModified": "2026-09-11T20:19:48.640", "metrics": {}, "published": "2026-09-11T20:19:48.640", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3be89e8039a85fa3b6cd5f9dcc4c1459eb356c2d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/411e484fe71a7f1028de617447edad9cb6d9d68a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/65deb18359341141d37dc86fc7853511be3c87a7"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: Linux Kernel: Information disclosure in SMB client due to small byte count in tree connect response", "id": "2532089", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2532089"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.7", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N", "status": "draft"}, "cwe": "CWE-125", "details": ["A flaw was found in the Linux kernel's Server Message Block (SMB) client. A remote malicious SMB server could send a specially crafted tree connect response with a byte count that is too small. This incorrect handling can lead to an integer underflow, causing the client to read beyond an allocated memory buffer. Consequently, sensitive information from kernel memory may be exposed to a local user through the `/proc/fs/cifs/DebugData` interface."], "name": "CVE-2026-89631", "package_state": [{"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "openshift/ose-rhel-coreos-8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-09-11T19:45:26Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-89631\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-89631\nhttps://git.kernel.org/stable/c/3be89e8039a85fa3b6cd5f9dcc4c1459eb356c2d\nhttps://git.kernel.org/stable/c/411e484fe71a7f1028de617447edad9cb6d9d68a\nhttps://git.kernel.org/stable/c/65deb18359341141d37dc86fc7853511be3c87a7"], "threat_severity": "Moderate"}

{}