{"id":"CVE-2026-99083","published":"2026-10-23T13:17:32.577","lastModified":"2026-10-26T07:17:18.627","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix heap out-of-bounds write in krb5_authenticate()\n\nIn krb5_authenticate(), out_len is calculated to determine available\nheadroom in response_buf for the incoming Kerberos AP-REP token. However,\nwhen SMB2_SESSION_SETUP is processed as a non-first element of a compounded\nSMB2 request, the calculation omits work->next_smb2_rsp_hdr_off.\n\nThis causes out_len to overstate remaining buffer headroom by\nthe cumulative size of prior responses in the compound chain. Consequently,\nthe length check in ksmbd_krb5_authenticate()\n(*out_len <= resp->spnego_blob_len) passes erroneously, allowing memcpy()\nto write the AP-REP blob past the end of response_buf into adjacent kernel\nheap memory.\n\nFix this by subtracting work->next_smb2_rsp_hdr_off when computing out_len,\nensuring it accurately reflects physical remaining buffer space.","cvssScore":8.8,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/23a0be6a84a38ac169eeab49017934e8e27c65f0","tags":[]},{"url":"https://git.kernel.org/stable/c/4722d06b2907585074252061b1024a696c1cfc23","tags":[]},{"url":"https://git.kernel.org/stable/c/517404e157395d0f8da125ca956c566895dfcd06","tags":[]},{"url":"https://git.kernel.org/stable/c/59c6dcc5dd9dafe764ca0d40525933b2be69b059","tags":[]},{"url":"https://git.kernel.org/stable/c/80af1bde97d5a85ad6f2c40ca894ccc8fa75a27a","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}