VulnerabilityPublished 28 Oct 2026

CVE-2026-99153: Linux kernel · scsi: libiscsi: Validate the ITT reflected in a Reject PDU

Source GCVE Database

Authoritative record:CVE-2026-99153

Not known to be exploited · fixed in d79343ae3223b3f7f74b55e79f8a1371fa3f4b1a : patch Linux kernel soon.

Data as of 28 Oct 2026, 14:02 UTC

Severity

High

Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD

Patch: Available – fixed in d79343ae3223b3f7f74b55e79f8a1371fa3f4b1a, c5958c770b2a0ee492414e26b07da9164a0d1f5d, 7215a69b6456fda79c0935c2959045dff3fcaac8

Exploitation evidence

Disclosed: evidence found.
CVE published 28 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-92v8-wfx9-6cf9

What to do

Upgrade Linux kernel to d79343ae3223b3f7f74b55e79f8a1371fa3f4b1a, c5958c770b2a0ee492414e26b07da9164a0d1f5d or 7215a69b6456fda79c0935c2959045dff3fcaac8.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 8afa1439fcff58da8f28c1d083046f229f6ab3de, < d79343ae3223b3f7f74b55e79f8a1371fa3f4b1a	Fixed in d79343ae3223b3f7f74b55e79f8a1371fa3f4b1a
LinuxLinux	Affected ≥ 8afa1439fcff58da8f28c1d083046f229f6ab3de, < c5958c770b2a0ee492414e26b07da9164a0d1f5d	Fixed in c5958c770b2a0ee492414e26b07da9164a0d1f5d
LinuxLinux	Affected ≥ 8afa1439fcff58da8f28c1d083046f229f6ab3de, < 7215a69b6456fda79c0935c2959045dff3fcaac8	Fixed in 7215a69b6456fda79c0935c2959045dff3fcaac8
LinuxLinux	Affected =2.6.32	Fixed in–
Red Hatredhat/kernel`pkg:rpm/redhat/kernel`Other threats	Affected =2.6.32	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix has been implemented in the Linux kernel to properly validate the ITT reflected in Reject PDUs, requiring the task to be in flight and not a SCSI command. Users should update to a kernel version that includes this fix once available. No other mitigation steps are indicated.

Description

A vulnerability in the Linux kernel's iSCSI implementation allows improper validation of the Initiator Task Tag (ITT) reflected in a Reject Protocol Data Unit (PDU). This can lead to the completion of in-flight SCSI commands incorrectly, potentially causing data corruption or kernel crashes. The issue arises because the ITT value from the target is not properly validated before being used to identify tasks, leading to possible reference count underflows and null pointer dereferences.

Impact

Improper validation of the ITT in Reject PDUs can cause kernel crashes due to null pointer dereferences and reference count underflows. Additionally, in-flight SCSI commands may be incorrectly completed as successful without actual data transfer, leading to potential data corruption or loss. This impacts the stability and reliability of the Linux kernel's iSCSI functionality.

Summary

The Linux kernel's iSCSI subsystem did not properly validate the ITT reflected in a Reject PDU. The iscsi_handle_reject() function copies the rejected PDU header and extracts the ITT to find the corresponding task. However, iscsi_itt_to_task() only bounds the index against cmds_max without further validation, allowing any task in the pool to be referenced. If the ITT corresponds to a task that was never used or already freed, this leads to null pointer dereferences or refcount underflows when iscsi_complete_task() is called. This can cause in-flight SCSI commands to be incorrectly completed as successful, potentially returning uninitialized data buffers and causing kernel crashes. The fix involves validating the reflected ITT similarly to how command ITTs are validated, ensuring the task is in flight and not a SCSI command.

References

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