{"id":"CVE-2026-99154","kind":"vulnerability","aliases":["CVE-2026-99154"],"related":[],"title":"Linux kernel iSCSI: negative task index lets a target read out of bounds","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: libiscsi: Reject a negative task index from parse_pdu_itt\n\nA transport that implements parse_pdu_itt hands libiscsi an index taken\nfrom the PDU, and both lookups bound it from above only:\n\n      if (i >= session->cmds_max)\n\ni and cmds_max are both int, so a negative index passes and\nsession->cmds[i] is read from before the array.\n\nbe2iscsi produces one. beiscsi_parse_pdu() assigns the raw tag,\n\n      *index = (int)itt;\n\nand beiscsi_complete_pdu() forwards an unsolicited NOP-In from the\nhardware async ring without replacing its ITT, so the value is the\ntarget's. It also reports the session's own age rather than the one in\nthe tag, which leaves the age comparison in iscsi_verify_itt() with\nnothing to reject.\n\nBound the index from below in both lookups.","summary":"The Linux kernel's libiscsi accepted a negative task index from a transport's PDU parser, so the driver read session command memory before the array. A target sending a crafted unsolicited NOP-In on a be2iscsi adapter can trigger this out-of-bounds read.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["be2iscsi","iscsi","kernel","linux","package","self-hosted"],"not_affected_if":["no-be2iscsi-hardware","no-iscsi"],"how_to_check":"- Run `uname -r` and compare against the fixed kernel builds in your distribution's advisory\n- Check whether the `be2iscsi` module is loaded with `lsmod | grep be2iscsi`\n- unknown for the exact affected version range, as the sources do not say","fix":"- Update the Linux kernel to a build that includes the libiscsi fix (version unknown from the sources)\n- Apply your distribution's kernel security update and reboot","status":"open","published_at":"2026-10-28T11:17:35+00:00","first_seen_at":"2026-10-28T11:32:36+00:00","triaged_at":"2026-10-28T11:35:53+00:00","updated_at":"2026-10-28T11:35:53+00:00","category":"package","confidence":0.5,"triage":{"at":"2026-10-28T11:35:53Z","model":"claude-haiku-5-5","output":{"fix":"- Update the Linux kernel to a build that includes the libiscsi fix (version unknown from the sources)\n- Apply your distribution's kernel security update and reboot","reach":"network","title":"Linux kernel iSCSI: negative task index lets a target read out of bounds","impact":"low","summary":"The Linux kernel's libiscsi accepted a negative task index from a transport's PDU parser, so the driver read session command memory before the array. A target sending a crafted unsolicited NOP-In on a be2iscsi adapter can trigger this out-of-bounds read.","category":"package","nicknames":[],"who_cares":["linux","kernel","iscsi","be2iscsi","self-hosted"],"confidence":0.5,"needs_auth":"unknown","worst_case":"out-of-bounds kernel memory read, possibly information disclosure or crash","analyst_note":"Check the NVD entry and the upstream kernel stable commit for the fixed kernel versions and any CVSS score.","how_to_check":"- Run `uname -r` and compare against the fixed kernel builds in your distribution's advisory\n- Check whether the `be2iscsi` module is loaded with `lsmod | grep be2iscsi`\n- unknown for the exact affected version range, as the sources do not say","needs_analyst":true,"not_affected_if":["no-iscsi","no-be2iscsi-hardware"],"who_is_affected":"Only hosts that use iSCSI initiator sessions through the be2iscsi driver are exposed, since the bad index comes from that driver's handling of the target's ITT. Systems without be2iscsi hardware or without iSCSI sessions can likely skip it.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"unknown"},"cost_usd":0.000657,"input_tokens":3525,"output_tokens":609,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2026':15A,18A '-99154':16A,19A 'accept':33B 'adapt':66B 'age':192C,203C 'also':186C 'array':53B,145C 'assign':152C 'async':172C 'be2iscsi':20B,65B,146C 'beiscsi':149C,160C 'bound':13A,73B,114C,213C 'cmds':122C,126C,138C 'command':49B 'comparison':204C 'complet':161C 'craft':58B 'cve':14A,17A 'driver':46B 'follow':80C 'forward':163C 'hand':103C 'hardwar':171C 'host':27B 'implement':99C 'index':6A,37B,91C,106C,134C,156C,215C 'int':130C,157C 'iscsi':3A,21B,206C 'itt':95C,102C,158C,177C,208C 'kernel':2A,22B,30B,78C 'leav':201C 'let':7A 'libiscsi':32B,86C,104C 'linux':1A,23B,29B,77C 'lookup':113C,220C 'max':123C,127C 'memori':50B 'negat':4A,35B,89C,133C 'nop':61B,167C 'nop-in':60B,166C 'noth':210C 'one':148C,196C 'out-of-bound':70B 'packag':24B 'pars':93C,100C,150C 'parser':43B 'pass':135C 'pdu':42B,94C,101C,110C,151C,162C 'produc':147C 'rather':193C 'raw':154C 'read':10A,47B,74B,141C 'reject':87C,212C 'replac':175C 'report':187C 'resolv':84C 'ring':173C 'scsi':85C 'self':26B 'self-host':25B 'send':56B 'session':48B,121C,137C,189C 'tag':155C,199C 'taken':107C 'target':9A,55B,183C 'task':5A,36B,90C 'transport':40B,97C 'trigger':68B 'unsolicit':59B,165C 'valu':180C 'verifi':207C 'vulner':81C 'without':174C","nicknames":[],"mitigations":[],"who_affected":"Only hosts that use iSCSI initiator sessions through the be2iscsi driver are exposed, since the bad index comes from that driver's handling of the target's ITT. Systems without be2iscsi hardware or without iSCSI sessions can likely skip it.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-28T11:17:35+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-99154","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-99154","severity":null,"published_at":"2026-10-28T11:17:35+00:00","modified_at":"2026-10-28T11:17:35+00:00","first_seen_at":"2026-10-28T11:32:36+00:00","fetched_at":"2026-10-28T11:32:36+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}