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Response snapshot Oct 31, 2026, 14:16 UTC

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VulnerabilityCVE-2026-99154

Linux kernel: scsi: libiscsi: Reject a negative task index from parse_pdu_itt

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.

At a glance

Exploited
Not known
Severity
9.8 Critical (CVSS 3.1)
Chance of exploitation
Not estimated
Sources
1 source

What to do

Check the vendor advisory for affected versions and fixes.

Read NVD CVE-2026-99154 (opens a new tab)

What happened

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)

Continue reading

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.

Scores and how they were measured

CVSS base severity

9.8

Version 3.1As of

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

Not available

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    NVD CVE-2026-99154 (opens a new tab)

    NVD record: description, CVSS (the CNA score is preferred), affected products, and publication date. Not evidence of exploitation.

    Published Checked

  2. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  3. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 31). Linux kernel: scsi: libiscsi: Reject a negative task index from parse_pdu_itt (CVE-2026-99154). https://kevwire.com/record/CVE-2026-99154

MLA

"Linux kernel: scsi: libiscsi: Reject a negative task index from parse_pdu_itt (CVE-2026-99154)." KEVWire, 31 Oct. 2026, kevwire.com/record/CVE-2026-99154.

Chicago

KEVWire. "Linux kernel: scsi: libiscsi: Reject a negative task index from parse_pdu_itt (CVE-2026-99154)." Last modified October 31, 2026. https://kevwire.com/record/CVE-2026-99154.

Evidence summary (plain text)

Linux kernel: scsi: libiscsi: Reject a negative task index from parse_pdu_itt (Oct 28, 2026).
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.
CVSS 9.8 (version 3.1; evidence as of Oct 31, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-99154).
Sources:
NVD CVE-2026-99154: https://nvd.nist.gov/vuln/detail/CVE-2026-99154
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-31T12:40:58.114Z&lastModEndDate=2026-10-31T14:15:57.636Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-31T10:50:56.512Z&lastModEndDate=2026-10-31T13:40:56.165Z&resultsPerPage=500&startIndex=0
Record ID: CVE-2026-99154.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 31, 2026, 14:15 UTC. Ingestion is not an independent editorial investigation.

NVD status: Received. Publication in the NVD is not evidence of exploitation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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