VulnerabilityPublished 24 Apr 2026Updated 15 Oct 2026

CVE-2026-31612: Linux kernel · ksmbd: validate EaNameLength in smb2_get_ea()

Affects Linux kernelSource GCVE Database

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Not known to be exploited · CVSS 7.5 High.

Data as of 12 Nov 2026, 03:20 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (Linux)	CVSS 3.1	7.5

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 24 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 11 Nov 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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.

What to do

AI-suggested

A fix for this vulnerability has been implemented in the Linux kernel by adding proper validation of the EaNameLength field in smb2_get_ea(). Users should apply the official Linux kernel updates that include this patch to remediate the issue. Since this is a kernel vulnerability, updating to the fixed kernel version is the recommended mitigation. No alternative workarounds are indicated.

Description

CVE-2026-31612 is a high-severity vulnerability in the Linux kernel's ksmbd component. It involves improper validation of the EaNameLength field in the smb2_get_ea() function, which can lead to uninitialized heap data being leaked to a client. The flaw arises because the length value is used directly in a strncmp() call without verifying that it matches the actual size of the input buffer. This vulnerability has been resolved by adding proper size checks to prevent misuse of the length as a trusted buffer size.

Impact

An attacker sending crafted SMB2 requests can exploit this vulnerability to leak uninitialized heap memory contents from the kernel to the client. This could expose sensitive information residing in kernel memory. The vulnerability does not allow code execution or denial of service but compromises confidentiality. The CVSS score of 7.5 reflects the high confidentiality impact with no integrity or availability impact.

Summary

The vulnerability in the Linux kernel's ksmbd module occurs in the smb2_get_ea() function, where the EaNameLength field from a client request is read and passed directly to strncmp() as the comparison length without verifying that the length corresponds to the actual input buffer size. This lack of validation allows strncmp() to operate on uninitialized heap memory, potentially leaking sensitive data to the client. The fix involves validating the EaNameLength against the overall request size to ensure the buffer length is trusted before use.

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Description

AI analysisMachine-generated, updated 12 Nov 2026, 03:20 UTC

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