In the Linux kernel, the following vulnerability has been resolved: smb: client: reject overlapping data areas in SMB2 responses Commit 53b7c271f06b ("smb: client: restrict implied bcc[0] exemption to responses without data area") restricted the implied bcc[0] length exception to responses without a data area. However, the overlap handling in __smb2_calc_size() clears data_length, which can make an invalid response appear to have no data area and so qualify for the exception. Track data area overlap separately and reject such responses before applying the length compatibility exceptions.

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-131721 advisory.

    In the Linux kernel, the following vulnerability has been resolved:

    smb: client: reject overlapping data areas in SMB2 responses

    Commit 53b7c271f06b (smb: client: restrict implied bcc[0] exemption to     responses without data area) restricted the implied bcc[0] length     exception to responses without a data area. However, the overlap     handling in __smb2_calc_size() clears data_length, which can make an     invalid response appear to have no data area and so qualify for the     exception.

    Track data area overlap separately and reject such responses before     applying the length compatibility exceptions.

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

An update of the linux package has been released.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - smb: client: reject overlapping data areas in SMB2 responses Commit 53b7c271f06b (smb: client: restrict     implied bcc[0] exemption to responses without data area) restricted the implied bcc[0] length exception     to responses without a data area. However, the overlap handling in __smb2_calc_size() clears data_length,     which can make an invalid response appear to have no data area and so qualify for the exception. Track     data area overlap separately and reject such responses before applying the length compatibility     exceptions. (CVE-2026-64257)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
366580	Unity Linux 20.1070e Security Update: kernel (UTSA-2026-131721)	Nessus	Unity Linux Local Security Checks	Local	critical
347900	SUSE SLED15 / SLES15 : Security update for the Linux Kernel (SUSE-SU-2026:4254-1)	Nessus	SuSE Local Security Checks	Local	high
343049	Oracle Linux 10 / 9 : Unbreakable Enterprise kernel (ELSA-2026-500248)	Nessus	Oracle Linux Local Security Checks	Local	high
332499	Photon OS 5.0: Linux PHSA-2026-5.0-92-0928	Nessus	PhotonOS Local Security Checks	Local	high
330152	Linux Distros Unpatched Vulnerability : CVE-2026-64257	Nessus	Misc.	Local	critical
329325	Photon OS 5.0: Linux PHSA-2026-5.0-0928	Nessus	PhotonOS Local Security Checks	Local	high

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CVE-2026-64257

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Tenable Plugins

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