Vulnerability · CVE-2026-99153

In the Linux kernel, the following vulnerability has been resolved: scsi: libiscsi: Validate the ITT reflected in a Reject PDU A Reject PDU carries a copy of the header it rejects,

Published Oct 28, 2026 · catalog updated Nov 1, 2026 · BSI

Last checked Nov 1, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-99153. EPSS is 0.55%. Act only if a listed version of BSI is installed.

Gaps on this record

No vendor fix or required action is stored. Compare the linked advisory before you change production.

Severity: Critical9.8
Known exploitation: Not in CISA/VulnCheck KEV
EPSS: 0.55%
Remediation: Advisory link
Affected products: Debian:12 linux · Debian:13 linux · Debian:14 linux

In the Linux kernel, the following vulnerability has been resolved: scsi: libiscsi: Validate the ITT reflected in a Reject PDU A Reject PDU carries a copy of the header it rejects, and iscsi_handle_reject() takes the ITT out of that copy to find the task to clean up: memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr)); ... task = iscsi_itt_to_task(conn, rejected_pdu.itt); That value is whatever the target put there. iscsi_itt_to_task() bounds the index against cmds_max and checks nothing else, so any task in the pool can be named, and iscsi_nop_out_rsp() then completes it. An index that has never been used gives a NULL task->conn: the pool is zeroed at session setup and conn is assigned only when a task is allocated. If the task was used and returned, iscsi_complete_task() hits its WARN_ON_ONCE(task->state == ISCSI_TASK_FREE) and the refcount underflows. An in-flight SCSI command is completed as successful - a 1 MiB read returned 1048576 with none of its buffer written and no warning. Validate the reflected ITT the way iscsi_itt_to_ctask() validates a command ITT, and require the task to be in flight and not a SCSI command. [ 6.248477] Oops: general protection fault, probably for non-canonical address 0xdffffc000000000c: 0000 [#1] SMP KASAN NOPTI [ 6.249357] KASAN: null-ptr-deref in range [0x0000000000000060-0x0000000000000067] [ 6.249951] CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 7.2.0-rc5-ISCSI1-gf5098b6bae76 #1 PREEMPT(lazy) [ 6.250718] Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 6.251616] RIP: 0010:iscsi_nop_out_rsp.constprop.0+0x46/0x160 [ 6.252043] Code: c1 ea 03 48 83 ec 08 80 3c 02 00 0f 85 f5 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 58 48 8d 7d 60 48 89 fa 48 c1 ea 03 3c 02 00 0f 85 c0 00 00 00 48 8b 45 60 48 39 c3 74 50 48 b8 00 [ 6.252813] RSP: 0018:ffff88806c907b80 EFLAGS: 00010206 [ 6.253042] RAX: dffffc0000000000 RBX: ffff88800607e000 RCX: ffffffff8d571a25 [ 6.253

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

Debian:12 linux6.1.106-1, 6.1.106-2, 6.1.106-3
Debian:13 linux6.12.100-1, 6.12.101-1, 6.12.105-1
Debian:14 linux6.12.100-1, 6.12.101-1, 6.12.105-1

How to fix CVE-2026-99153

No stored fix
No vendor fix text is stored. Use the linked advisory before you change production.
Version check
Seen in 6.1.106-1 · 8 other packages on the advisory
Advisory
Open the bsi record and follow its fix.
Official advisories

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-99153. EPSS is 0.55%. Act only if a listed version of BSI is installed.

Which versions are affected?

Compare what you have installed with 6.1.106-1, 6.1.106-2, 6.1.106-3, 6.12.100-1, 6.12.101-1, 6.12.105-1. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.55%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Debian security F5 BIG-IP security

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

Oct 29, 2026 · BSI CERT-Bund
Detected
CVE-2026-99153 is listed by Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff.
Nov 1, 2026 · Trivy Vulnerability DB
Updated
In the Linux kernel, the following vulnerability has been resolved: scsi: libiscsi: Validate the ITT reflected in a Reject PDU A Reject PDU carries a copy of the header it rejects, and iscsi_handle_reject() takes the ITT out of that copy to find the task to clean up: memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr)); ... task = iscsi_itt_to_task(conn, rejected_pdu.itt); That value is whatever

Sources

BSI CERT-BundGovernment advisoryCVE-2026-99153
Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff
wid.cert-bund.de
CVE.orgVulnerability recordCVE-2026-99153
Official CVE identifier
cve.org
FIRST EPSSExploitation probabilityCVE-2026-99153
30-day exploitation probability 0.55%
first.org
Tenable CVE DatabaseVulnerability recordCVE-2026-99153
In the Linux kernel, the following vulnerability has been resolved: scsi: libiscsi: Validate the ITT reflected in a Reject PDU A Reject PDU carries a copy of the header it rejects, and iscsi_handle_reject() takes the ITT out of that copy to find the task to clean up: memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr)); ... task = iscsi_itt_to_task(conn, rejected_pdu.itt); That value is whatever
tenable.com
Trivy Vulnerability DBPackage advisoryDEBIAN-CVE-2026-99153
In the Linux kernel, the following vulnerability has been resolved: scsi: libiscsi: Validate the ITT reflected in a Reject PDU A Reject PDU carries a copy of the header it rejects, and iscsi_handle_reject() takes the ITT out of that copy to find the task to clean up: memcpy(&reje
osv.dev

References

ADVISORY · security-tracker.debian.org

Freshness

Last verified in this catalog Nov 1, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

FIRST EPSSNov 1, 2026
Trivy Vulnerability DBNov 1, 2026
Tenable CVE DatabaseNov 1, 2026
CVE.orgOct 30, 2026
BSI CERT-BundOct 30, 2026

Priority score

27/100

Evidence confidence: High

A vendor or government advisory agrees with at least one other source.

Confirmed exploitation0/30
EPSS probability1/20
CVSS severity15/15
Public exploit0/10
Internet exposure6/10
Product prevalence5/5
Detection0/5
Threat research0/5

Decision signals

Four separate signals — do not infer one from another.

Critical

CVSS severity
9.8 v3.1
Technical impact. Separate from exploitation likelihood.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS probability
0.55% · p46.13%
Estimated probability of exploitation within 30 days (FIRST).
Known exploitation
No verified KEV listing
Evidence from CISA KEV or VulnCheck KEV only — not from EPSS alone.
Patch availability
Advisory link
A patch or advisory reference is linked. Open the original publisher for availability by product version.

Stacks

Debian Debian 12 Debian 13 Debian 14 F5 Linux

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