CVE-2026-46139

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: use kzalloc to zero-initialize security descriptor buffer Commit 62e7dd0a39c2d ("smb: common: change the data type of num_aces to le16") split struct smb_acl's __le32 num_aces field into __le16 num_aces and __le16 reserved. The reserved field corresponds to Sbz2 in the MS-DTYP ACL wire format, which must be zero [1]. When building an ACL descriptor in build_sec_desc(), we are using a kmalloc()'ed descriptor buffer and writing the fields explicitly using le16() writes now. This never writes to the 2 byte reserved field, leaving it as uninitialized heap data. When the reserved field happens to contain non-zero slab garbage, Samba rejects the security descriptor with "ndr_pull_security_descriptor failed: Range Error", causing chmod to fail with EINVAL. Change kmalloc() to kzalloc() to ensure the entire buffer is zero-initialized. [1] https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-dtyp/20233ed8-a6c6-4097-aafa-dd545ed24428

Overview

State: PUBLISHED
Assigner (CNA): Linux
CVSS severity: high
CVSS score: 7.1 / 10
CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
Effective score: 7.1 / 10 HIGH source: CNA overview
CWE(s): —
Reserved: 2026-05-13
Published: 2026-05-28 09:35 UTC
Last updated: 2026-05-28 09:35 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/46xxx/CVE-2026-46139.json
Linked Threat: CVE-2026-46139 — CVE-2026-46139

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published: 2026-05-28 10:16:29 UTC
NVD last modified: 2026-06-24 17:26:46 UTC
NVD CVSS v3.1: 5.5 / 10 MEDIUM source: nvd@nist.gov
NVD CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Exploitability subscore: 1.8 / 10
Impact subscore: 3.6 / 10
EPSS score: 0.0012 (probability of exploitation in next 30 days)
EPSS percentile: 2.34% vs all CVEs — higher = more likely to be exploited, as of 2026-07-27

NVD-assigned CWE(s): CWE-908 (differs from the CNA list above)

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID: EUVD-2026-32766
Assigner: Linux
Published: May 28, 2026, 9:35:55 AM
Updated: Jun 14, 2026, 5:57:22 PM
EUVD base score: 0.0 / 10
EUVD-reported EPSS: 0.1200
Vendors: Linux
Products: Linux (191f2f444745087c3c51fd6042a0e25f42315ab0)

Linux (da087905e3270e2291c0afae39a28e7d183e5ec3 <941a1e6eb35440336913afc88a82103291956d5d)

Linux (62e7dd0a39c2d0d7ff03274c36df971f1b3d2d0d <be1ef9512a3f5a755895c24f31b334342f4aa15b)

Linux (62e7dd0a39c2d0d7ff03274c36df971f1b3d2d0d <5e489c6c47a2ac15edbaca153b9348e42c1eacab)

Linux (6.12.23 <6.12.88)

Linux (62e7dd0a39c2d0d7ff03274c36df971f1b3d2d0d <9bdb2ca31368b7671949dfb94a5d57ffccd01edd)

Linux (1593ddb37bd124c131fe635397df68e854a03108 <4c3ed344a970aad51388ac3b0145b98318f0e21f)

Linux (patch: 6.12.88)

Linux (6.14)

Linux (patch: 7.1)

Linux (patch: 7.0.7)

Linux (patch: 6.18.30)

Linux (patch: 0)

Linux (6.13.11 <6.14)
Aliases: GHSA-v8jf-78w3-v9hm

ENISA description: In the Linux kernel, the following vulnerability has been resolved: smb: client: use kzalloc to zero-initialize security descriptor buffer Commit 62e7dd0a39c2d ("smb: common: change the data type of num_aces to le16") split struct smb_acl's __le32 num_aces field into __le16 num_aces and __le16 reserved. The reserved field corresponds to Sbz2 in the MS-DTYP ACL wire format, which must be zero [1]. When building an ACL descriptor in build_sec_desc(), we are using a kmalloc()'ed descriptor buffer and writing the fields explicitly using le16() writes now. This never writes to the 2 byte reserved field, leaving it as uninitialized heap data. When the reserved field happens to contain non-zero slab garbage, Samba rejects the security descriptor with "ndr_pull_security_descriptor failed: Range Error", causing chmod to fail with EINVAL. Change kmalloc() to kzalloc() to ensure the entire buffer is zero-initialized. [1] https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-dtyp/20233ed8-a6c6-4097-aafa-dd545ed24428

EUVD references (5)

Affected products (2)

Vendor	Product	Versions	Platforms
Linux	Linux	`1593ddb37bd124c131fe635397df68e854a03108` (affected), `da087905e3270e2291c0afae39a28e7d183e5ec3` (affected), `62e7dd0a39c2d0d7ff03274c36df971f1b3d2d0d` (affected), `62e7dd0a39c2d0d7ff03274c36df971f1b3d2d0d` (affected), `62e7dd0a39c2d0d7ff03274c36df971f1b3d2d0d` (affected), `191f2f444745087c3c51fd6042a0e25f42315ab0` (affected), `6.12.23` (affected), `6.13.11` (affected)	—
Linux	Linux	`6.14` (affected), `0` (unaffected), `6.12.88` (unaffected), `6.18.30` (unaffected), `7.0.7` (unaffected), `7.1-rc3` (unaffected)	—

Affected products — CPE 2.3 (6) NVD

NVD's normalized CPE 2.3 matchers, used by vendor tools (vulnerability scanners, asset managers) for automated detection. Compare with the CNA's free-text "Affected products" section above.

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:-:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc6:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc7:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*

Vendor references (5)

References embedded in the original CVE record by the assigning CNA.

Web references (8)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

https://git.kernel.org/stable/c/4c3ed344a970aad51388ac3b0145b98318f0e21f tenable:git.kernel.org
https://git.kernel.org/stable/c/5e489c6c47a2ac15edbaca153b9348e42c1eacab tenable:git.kernel.org
https://git.kernel.org/stable/c/941a1e6eb35440336913afc88a82103291956d5d tenable:git.kernel.org
https://git.kernel.org/stable/c/9bdb2ca31368b7671949dfb94a5d57ffccd01edd tenable:git.kernel.org
https://git.kernel.org/stable/c/be1ef9512a3f5a755895c24f31b334342f4aa15b tenable:git.kernel.org
https://nvd.nist.gov/vuln/detail/CVE-2026-46139 tenable:nvd.nist.gov
https://www.cve.org/CVERecord?id=CVE-2026-46139 tenable:www.cve.org
https://www.first.org/epss/ tenable:www.first.org

NVD-tagged references (5)

Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.

https://git.kernel.org/stable/c/4c3ed344a970aad51388ac3b0145b98318f0e21f 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/5e489c6c47a2ac15edbaca153b9348e42c1eacab 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/941a1e6eb35440336913afc88a82103291956d5d 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/9bdb2ca31368b7671949dfb94a5d57ffccd01edd 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/be1ef9512a3f5a755895c24f31b334342f4aa15b 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch

Remediations (17)

Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.

Security Updates - Red Hat Customer Portal

web:access.redhat.com

Learn about our open source products, services, and company. You are here

2026-06-04 00:00 UTC
Microsoft and Adobe Patch Tuesday, May 2026 Security Update Review

web:blog.qualys.com

May 2026's Patch Tuesday arrives with Microsoft addressing a fresh set of vulnerabilities across its ecosystem, reinforcing the ongoing need for timely patching in an increasingly threat-heavy…

2026-06-04 00:00 UTC
Microsoft Patch Tuesday May 2026 - 120 Vulnerabilities Fixed, Including ...

web:cybersecuritynews.com

Microsoft's May 2026 Patch Tuesday lands with a heavy enterprise focus, fixing 120 vulnerabilities across Windows, Office, Azure, developer tools, and Microsoft 365 apps, including 29 remote code execution (RCE) flaws rated Critical.

2026-06-04 00:00 UTC
Security Update Guide - Microsoft

web:portal.msrc.microsoft.com

The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.

2026-06-04 00:00 UTC
Landing Page | ServiceNow Common Vulnerabilities & Exposures (CVE ...

web:support.servicenow.com

Overview The advisories below document publicly disclosed Common Vulnerabilities and Exposures ( CVEs ) in the Now Platform by ServiceNow. Because ServiceNow uses various methods to communicate vulnerability information, patches, and other fixes, customers should review family, security patch , and hotfix release notes, which are available at https://docs.servicenow.com, for a complete list of ...

2026-06-04 00:00 UTC
Microsoft May 2026 Patch Tuesday: Many fixes, but no zero-days

web:www.helpnetsecurity.com

Microsoft has marked May 2026 Patch Tuesday by releasing fixes for 120+ CVE -numbered vulnerabilities, none of which are actively exploited.

2026-06-04 00:00 UTC
Oracle Critical Patch Update Advisory - April 2026

web:www.oracle.com

This Critical Patch Update contains 481 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at April 2026 Critical Patch Update: Executive Summary and Analysis.

2026-06-04 00:00 UTC
Patch Tuesday May 2026 - PDQ

web:www.pdq.com

May 2026 Patch Tuesday is here, and PDQ is back with another recap. Will we see another month of increased CVE volume? Is AI to blame? Dive in to learn more.

2026-06-04 00:00 UTC
Patch Tuesday - May 2026 - Rapid7

web:www.rapid7.com

Microsoft is publishing 137 vulnerabilities on May 2026 Patch Tuesday, including critical RCE in Netlogon and the Windows DNS client.

2026-06-04 00:00 UTC
VirusTotal - Home

web:www.virustotal.com

VirusTotal is a platform for scanning files and URLs for viruses, malware, and other threats using multiple antivirus engines.

2026-06-04 00:00 UTC
Microsoft Confirms Defender RoguePlanet 0-Day Exploit and Working to ...

web:cybersecuritynews.com

Microsoft has officially acknowledged a critical zero-day vulnerability in Microsoft Defender, publicly dubbed "RoguePlanet," and confirmed it is actively developing a security patch to address the flaw.

2026-06-19 02:28 UTC
May 2026 Patch Tuesday: Updates and Analysis | CrowdStrike

web:www.crowdstrike.com

Microsoft has released security updates for 130 vulnerabilities, including 30 critical, in its May 2026 Patch Tuesday rollout.

2026-06-19 02:28 UTC
Microsoft Technical Security Notifications

web:www.microsoft.com

Security Update Guide Notifications Microsoft's free Security Update Guide Notifications provide links to security-related software updates and notification of re-released security updates. These notifications are sent via email throughout the month as needed.

2026-06-19 02:28 UTC
Oracle Critical Security Patch Update Advisory - May 2026

web:www.oracle.com

Prior Critical Patch Update and Critical Security Patch Update advisories should be reviewed for information regarding earlier published security patches. Refer to Critical Patch Updates, Critical Security Patch Updates, Security Alerts and Bulletins for information about Oracle Security advisories.

2026-06-19 02:28 UTC
Patch Tuesday - June 2026 - Rapid7

web:www.rapid7.com

Microsoft is publishing 200 vulnerabilities on June 2026 Patch Tuesday, including an HTTP/2 denial of service vulnerability and an elevation of privilege vulnerability in PowerToys.

2026-06-19 02:28 UTC
Vulnerabilities Resolved in Veeam Backup & Replication 13.0.1.2067

web:www.veeam.com

When a vulnerability is identified, our team promptly develops a patch to address and mitigate the risk. In line with our dedication to transparency, we publicly disclose the vulnerability and provide detailed mitigation information.

2026-06-19 02:28 UTC
Patch Tuesday June 2026: Security Updates & CVE Analysis

web:zecurit.com

Get the complete breakdown of Microsoft's June 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .

2026-06-19 02:28 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-46139.json.

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/client/cifsacl.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "lessThan": "4c3ed344a970aad51388ac3b0145b98318f0e21f",
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              "versionType": "git"
            },
            {
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            {
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              "status": "affected",
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              "versionType": "git"
            },
            {
              "lessThan": "9bdb2ca31368b7671949dfb94a5d57ffccd01edd",
              "status": "affected",
              "version": "62e7dd0a39c2d0d7ff03274c36df971f1b3d2d0d",
              "versionType": "git"
            },
            {
              "lessThan": "5e489c6c47a2ac15edbaca153b9348e42c1eacab",
              "status": "affected",
              "version": "62e7dd0a39c2d0d7ff03274c36df971f1b3d2d0d",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "191f2f444745087c3c51fd6042a0e25f42315ab0",
              "versionType": "git"
            },
            {
              "lessThan": "6.12.88",
              "status": "affected",
              "version": "6.12.23",
              "versionType": "semver"
            },
            {
              "lessThan": "6.14",
              "status": "affected",
              "version": "6.13.11",
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            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
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          ],
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          "vendor": "Linux",
          "versions": [
            {
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            },
            {
              "lessThan": "6.14",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.88",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.30",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1-rc3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.88",
                  "versionStartIncluding": "6.12.23",
                  "vulnerable": true
                },
                {
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                {
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                },
                {
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                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "vulnerable": true
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              "negate": false,
              "operator": "OR"
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        }
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: use kzalloc to zero-initialize security descriptor buffer\n\nCommit 62e7dd0a39c2d (\"smb: common: change the data type of num_aces\nto le16\") split struct smb_acl's __le32 num_aces field into __le16\nnum_aces and __le16 reserved. The reserved field corresponds to Sbz2\nin the MS-DTYP ACL wire format, which must be zero [1].\n\nWhen building an ACL descriptor in build_sec_desc(), we are using a\nkmalloc()'ed descriptor buffer and writing the fields explicitly using\nle16() writes now. This never writes to the 2 byte reserved field,\nleaving it as uninitialized heap data.\n\nWhen the reserved field happens to contain non-zero slab garbage,\nSamba rejects the security descriptor with \"ndr_pull_security_descriptor\nfailed: Range Error\", causing chmod to fail with EINVAL.\n\nChange kmalloc() to kzalloc() to ensure the entire buffer is\nzero-initialized.\n\n\n[1] https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-dtyp/20233ed8-a6c6-4097-aafa-dd545ed24428"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-28T09:35:55.234Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/4c3ed344a970aad51388ac3b0145b98318f0e21f"
        },
        {
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        },
        {
          "url": "https://git.kernel.org/stable/c/be1ef9512a3f5a755895c24f31b334342f4aa15b"
        },
        {
          "url": "https://git.kernel.org/stable/c/9bdb2ca31368b7671949dfb94a5d57ffccd01edd"
        },
        {
          "url": "https://git.kernel.org/stable/c/5e489c6c47a2ac15edbaca153b9348e42c1eacab"
        }
      ],
      "title": "smb: client: use kzalloc to zero-initialize security descriptor buffer",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-46139",
    "datePublished": "2026-05-28T09:35:55.234Z",
    "dateReserved": "2026-05-13T15:03:33.100Z",
    "dateUpdated": "2026-05-28T09:35:55.234Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}