CVE-2026-99154

scsi: libiscsi: Reject a negative task index from parse_pdu_itt

Published Oct 28, 2026 CVSS 3.1 · 9.8 Critical EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

scsi: libiscsi: Reject a negative task index from parse_pdu_itt

A transport that implements parse_pdu_itt hands libiscsi an index taken
from the PDU, and both lookups bound it from above only:

if (i >= session->cmds_max)

i and cmds_max are both int, so a negative index passes and
session->cmds[i] is read from before the array.

be2iscsi produces one. beiscsi_parse_pdu() assigns the raw tag,

*index = (int)itt;

and beiscsi_complete_pdu() forwards an unsolicited NOP-In from the
hardware async ring without replacing its ITT, so the value is the
target's. It also reports the session's own age rather than the one in
the tag, which leaves the age comparison in iscsi_verify_itt() with
nothing to reject.

Bound the index from below in both lookups.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4904-1 linux-6.12 security update
History
Type Values Removed Values Added
Weaknesses CWE-787
Type Values Removed Values Added
Weaknesses CWE-787
Type Values Removed Values Added
Weaknesses CWE-125
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
First Time appeared Linux linux
Vendors & Products Linux linux
Type Values Removed Values Added
Weaknesses CWE-125
Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: scsi: libiscsi: Reject a negative task index from parse_pdu_itt A transport that implements parse_pdu_itt hands libiscsi an index taken from the PDU, and both lookups bound it from above only: if (i >= session->cmds_max) i and cmds_max are both int, so a negative index passes and session->cmds[i] is read from before the array. be2iscsi produces one. beiscsi_parse_pdu() assigns the raw tag, *index = (int)itt; and beiscsi_complete_pdu() forwards an unsolicited NOP-In from the hardware async ring without replacing its ITT, so the value is the target's. It also reports the session's own age rather than the one in the tag, which leaves the age comparison in iscsi_verify_itt() with nothing to reject. Bound the index from below in both lookups.
Title scsi: libiscsi: Reject a negative task index from parse_pdu_itt
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Oct 31, 2026, 12:44 PM
Reserved
Sep 25, 2026, 10:25 AM
Status
Received
Published
Oct 28, 2026, 11:17 AM
Modified
Oct 31, 2026, 1:17 PM
Severity
Moderate
Public date
Oct 28, 2026, 10:35 AM