# CVE-2026-99153: scsi: libiscsi: Validate the ITT reflected in a Reject PDU


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 28 Oct 2026
- **Updated:** 28 Oct 2026
- **Also known as:** AZL-111287, BELL-CVE-2026-99153, DEBIAN-CVE-2026-99153, GHSA-92v8-wfx9-6cf9, UBUNTU-CVE-2026-99153

## What is CVE-2026-99153?

CVE-2026-99153 is a vulnerability in Linux, published on 28 Oct 2026. 

### Official description

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 <80> 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
[    6.253345] RDX: 000000000000000c RSI: ffff88806c907c38 RDI: 0000000000000060
[    6.253642] RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff235a504
[    6.253947] R10: 0000000000000003 R11: 7463656e6e6f6320 R12: 0000000000000000
[    6.254251] R13: 0000000000000000 R14: ffff88806c907c38 R15: 0000000000000000
[    6.254549] FS:  0000000000000000(0000) GS:ffff8880d95bc000(0000) knlGS:0000000000000000
[    6.254887] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    6.255140] CR2: 00007fc393e8ffc0 CR3: 0000000005252006 CR4: 0000000000770ef0
[    6.255439] PKRU: 55555554
[    6.255564] Call Trace:
[    6.255674]  <IRQ>
[    6.255768]  __iscsi_complete_pdu+0x18bf/0x22a0
[    6.256733]  iscsi_complete_pdu+0x54/0xa0
[    6.256905]  iscsi_tcp_data_recv_done+0xf4/0x250
[    6.257103]  iscsi_tcp_recv_skb+0x31e/0xec0
[    6.257680]  iscsi_sw_tcp_recv+0x12f/0x390
[    6.258061]  __tcp_read_sock+0x1ab/0x810
[    6.258853]  iscsi_sw_tcp_data_ready+0x18b/0x510
[    6.259808]  tcp_data_queue+0x1f13/0x4cd0
[    6.260567]  tcp_rcv_established+0x8a5/0x3a00
[    6.261931]  tcp_v4_do_rcv+0x449/0x960
[    6.262269]  tcp_v4_rcv+0x2245/0x3bc0

## Which versions are affected by CVE-2026-99153?


## How do I fix CVE-2026-99153?

Upgrade to a fixed version.

## Is CVE-2026-99153 being exploited?

There is no known exploitation of CVE-2026-99153 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-99153 and fix it if it is affected.

What it is: CVE-2026-99153 is a vulnerability in Linux, published on 28 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-99153 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-99153/ (Markdown: https://insights.sbomify.com/CVE-2026-99153/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-99153
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-99153
- OSV: https://osv.dev/vulnerability/CVE-2026-99153

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-99153/
Summaries are generated and may contain mistakes; the official description above is the record.