{"id":"CVE-2026-74557","state":"PUBLISHED","title":"scsi: libiscsi: Fix stale-data leak into the SCSI sense buffer","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: libiscsi: Fix stale-data leak into the SCSI sense buffer\n\niscsi_scsi_cmd_rsp() copies the sense data of a SCSI Response from the\ntarget-supplied data segment.  The segment carries a 2-byte sense length\nfollowed by the sense bytes, so it must hold 2 + senselen bytes, but the\nbounds check only requires datalen >= senselen:\n\n\tsenselen = get_unaligned_be16(data);\n\tif (datalen < senselen)\n\t\tgoto invalid_datalen;\n\tmemcpy(sc->sense_buffer, data + 2,\n\t       min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));\n\nA target that returns a SCSI Response whose datalen equals senselen\n(with senselen <= SCSI_SENSE_BUFFERSIZE) makes the memcpy() from data +\n2 read up to two bytes past the received data.  Those bytes are stale\nconn->data contents and end up in the command's sense buffer, which is\nreturned to userspace.\n\nAccount for the 2-byte sense length prefix in the check.","publishedAt":"2026-08-15T12:28:01.988Z","updatedAt":"2026-10-16T19:05:55.724Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7996a778ff8c717cb1a7a294475c59cc8f1e9fb8","status":"affected","lessThan":"812f1ae95b22419422972748f173b0916ee4d621","versionType":"git"},{"version":"7996a778ff8c717cb1a7a294475c59cc8f1e9fb8","status":"affected","lessThan":"fef6167e8149896cd81bea333fd51b1c91239149","versionType":"git"},{"version":"7996a778ff8c717cb1a7a294475c59cc8f1e9fb8","status":"affected","lessThan":"baa04572673125e4d5bc309b4077d1cb46cc78d1","versionType":"git"},{"version":"7996a778ff8c717cb1a7a294475c59cc8f1e9fb8","status":"affected","lessThan":"7567f06abdefb1caf2d836107c4d08c5185c650e","versionType":"git"},{"version":"7996a778ff8c717cb1a7a294475c59cc8f1e9fb8","status":"affected","lessThan":"60499924faf4ef97e84228c20515218ef121facf","versionType":"git"},{"version":"7996a778ff8c717cb1a7a294475c59cc8f1e9fb8","status":"affected","lessThan":"3ef209ca0b4b68c75e9a814d90cc916026b5a6ac","versionType":"git"},{"version":"7996a778ff8c717cb1a7a294475c59cc8f1e9fb8","status":"affected","lessThan":"1f07a897d43c63e6c9458bf77450defef39b5833","versionType":"git"},{"version":"7996a778ff8c717cb1a7a294475c59cc8f1e9fb8","status":"affected","lessThan":"98b87885de4b7f605533a2860685f5689fce8e82","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/scsi/libiscsi.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.18","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.18","versionType":"semver"},{"version":"5.10.265","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.216","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.151","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.103","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.44","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.8","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/scsi/libiscsi.c"]}],"references":["https://git.kernel.org/stable/c/812f1ae95b22419422972748f173b0916ee4d621","https://git.kernel.org/stable/c/fef6167e8149896cd81bea333fd51b1c91239149","https://git.kernel.org/stable/c/baa04572673125e4d5bc309b4077d1cb46cc78d1","https://git.kernel.org/stable/c/7567f06abdefb1caf2d836107c4d08c5185c650e","https://git.kernel.org/stable/c/60499924faf4ef97e84228c20515218ef121facf","https://git.kernel.org/stable/c/3ef209ca0b4b68c75e9a814d90cc916026b5a6ac","https://git.kernel.org/stable/c/1f07a897d43c63e6c9458bf77450defef39b5833","https://git.kernel.org/stable/c/98b87885de4b7f605533a2860685f5689fce8e82"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74557.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74557","state":"PUBLISHED","datePublished":"2026-08-15T12:28:01.988Z","dateUpdated":"2026-10-16T19:05:55.724Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.916Z"},"containers":{"cna":{"title":"scsi: libiscsi: Fix stale-data leak into the SCSI sense buffer","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: libiscsi: Fix stale-data leak into the SCSI sense buffer\n\niscsi_scsi_cmd_rsp() copies the sense data of a SCSI Response from the\ntarget-supplied data segment.  The segment carries a 2-byte sense length\nfollowed by the sense bytes, so it must hold 2 + senselen bytes, but the\nbounds check only requires datalen >= senselen:\n\n\tsenselen = get_unaligned_be16(data);\n\tif (datalen < senselen)\n\t\tgoto invalid_datalen;\n\tmemcpy(sc->sense_buffer, data + 2,\n\t       min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));\n\nA target that returns a SCSI Response whose datalen equals senselen\n(with senselen <= SCSI_SENSE_BUFFERSIZE) makes the memcpy() from data +\n2 read up to two bytes past the received data.  Those bytes are stale\nconn->data contents and end up in the command's sense buffer, which is\nreturned to userspace.\n\nAccount for the 2-byte sense length prefix in the check."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7996a778ff8c717cb1a7a294475c59cc8f1e9fb8","status":"affected","lessThan":"812f1ae95b22419422972748f173b0916ee4d621","versionType":"git"},{"version":"7996a778ff8c717cb1a7a294475c59cc8f1e9fb8","status":"affected","lessThan":"fef6167e8149896cd81bea333fd51b1c91239149","versionType":"git"},{"version":"7996a778ff8c717cb1a7a294475c59cc8f1e9fb8","status":"affected","lessThan":"baa04572673125e4d5bc309b4077d1cb46cc78d1","versionType":"git"},{"version":"7996a778ff8c717cb1a7a294475c59cc8f1e9fb8","status":"affected","lessThan":"7567f06abdefb1caf2d836107c4d08c5185c650e","versionType":"git"},{"version":"7996a778ff8c717cb1a7a294475c59cc8f1e9fb8","status":"affected","lessThan":"60499924faf4ef97e84228c20515218ef121facf","versionType":"git"},{"version":"7996a778ff8c717cb1a7a294475c59cc8f1e9fb8","status":"affected","lessThan":"3ef209ca0b4b68c75e9a814d90cc916026b5a6ac","versionType":"git"},{"version":"7996a778ff8c717cb1a7a294475c59cc8f1e9fb8","status":"affected","lessThan":"1f07a897d43c63e6c9458bf77450defef39b5833","versionType":"git"},{"version":"7996a778ff8c717cb1a7a294475c59cc8f1e9fb8","status":"affected","lessThan":"98b87885de4b7f605533a2860685f5689fce8e82","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/scsi/libiscsi.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.18","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.18","versionType":"semver"},{"version":"5.10.265","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.216","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.151","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.103","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.44","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.8","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/scsi/libiscsi.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/812f1ae95b22419422972748f173b0916ee4d621"},{"url":"https://git.kernel.org/stable/c/fef6167e8149896cd81bea333fd51b1c91239149"},{"url":"https://git.kernel.org/stable/c/baa04572673125e4d5bc309b4077d1cb46cc78d1"},{"url":"https://git.kernel.org/stable/c/7567f06abdefb1caf2d836107c4d08c5185c650e"},{"url":"https://git.kernel.org/stable/c/60499924faf4ef97e84228c20515218ef121facf"},{"url":"https://git.kernel.org/stable/c/3ef209ca0b4b68c75e9a814d90cc916026b5a6ac"},{"url":"https://git.kernel.org/stable/c/1f07a897d43c63e6c9458bf77450defef39b5833"},{"url":"https://git.kernel.org/stable/c/98b87885de4b7f605533a2860685f5689fce8e82"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","baseScore":7.5,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - A remote malicious or compromised iSCSI target can trigger the bug by sending a crafted SCSI Command Response over the standard iSCSI/TCP session to a Linux kernel initiator, with no local access required on the victim host.\nAC:L - The attacker fully controls the response PDU fields (datalen, sense length, CHECK_CONDITION status) and can reliably set datalen equal to senselen so the flawed bounds check passes and stale conn->data bytes are copied into the sense buffer.\nPR:N - Exploitation requires only the ability to act as the iSCSI target on the network; the attacker needs no local account, capabilities, or privileges on the victim system initiating the connection.\nUI:N - Once an iSCSI session exists, the leak is triggered automatically on SCSI command responses with no further victim action; the attacker does not rely on a user opening a file, clicking a link, or performing any interactive step at exploit time.\nS:U - The flaw discloses kernel memory contents into a SCSI sense buffer returned within the same host security domain; it does not cross VM, hypervisor, or IOMMU boundaries and is a standard kernel-to-userspace information leak.\nC:H - The out-of-bounds memcpy reads up to two bytes per response from stale conn->data kernel heap memory into sc->sense_buffer, which is copied to userspace via SCSI completion, ioctl, and BSG paths, enabling repeated kernel information disclosure.\nI:N - The vulnerability is a read-only out-of-bounds memcpy from the receive buffer into the sense buffer; it does not corrupt kernel structures, overwrite memory, or provide a write or code-execution primitive.\nA:N - The bug causes no kernel panic, oops, or hang; invalid responses are handled gracefully and exploitation only leaks data into the sense buffer without disrupting system availability."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-19T16:38:59.951Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.18","versionEndExcluding":"5.10.265"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.18","versionEndExcluding":"5.15.216"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.18","versionEndExcluding":"6.1.183"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.18","versionEndExcluding":"6.6.151"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.18","versionEndExcluding":"6.12.103"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.18","versionEndExcluding":"6.18.44"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.18","versionEndExcluding":"7.1.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.18","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-74557","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T19:00:09.303445Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T19:05:55.724Z"}}]}}}