CVE-2026-99272

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: validate the data area in SMB2_read() SMB2_read() copies le32_to_cpu(rsp->DataLength) bytes from (char *)rsp + rsp->DataOffset without checking that the range lies within the response actually received. A READ response with DataOffset == 0 makes smb2_get_data_area_len() zero the data length, so smb2_check_message() accepts a frame as short as the fixed response, while SMB2_read() still uses the server-supplied DataLength, capped only by CIFS_MAX_MSGSIZE and the caller's length. A malicious server can answer the synchronous read used by the mfsymlinks (or SFU) symlink parser with an 81-byte READ response carrying DataOffset 0 and DataLength 1067, making the client copy 1067 bytes from a 448-byte receive object (KASAN slab-out-of-bounds; up to 16 KiB in the general case). Clamp a zero (or header-overlapping) DataOffset to read_rsp_size, as handle_read_data() does for the asynchronous path, and reject the response unless DataOffset + DataLength fits within rsp_iov.iov_len. The SMB1 helper was fixed the same way in 5be5bdda5863.

Overview

State: PUBLISHED
Assigner (CNA): Linux
CVSS severity: —
CVSS score: —
CVSS vector: —
Effective score: no score available from CNA, NVD, or AI yet
CWE(s): —
Reserved: 2026-09-25
Published: 2026-11-07 14:08 UTC
Last updated: 2026-11-07 14:08 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/99xxx/CVE-2026-99272.json

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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-2026-119290

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Affected products (2)

Vendor	Product	Versions	Platforms
Linux	Linux	`d8e050398d23ef7c019c96200b80d73f4e5cec0c` (affected), `d8e050398d23ef7c019c96200b80d73f4e5cec0c` (affected)	—
Linux	Linux	`3.7` (affected), `0` (unaffected), `7.3.2` (unaffected), `7.4-rc1` (unaffected)	—

Vendor references (2)

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

Web references (0)

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

No web references attached yet.

Remediations (10)

CVE Database Search & Remediation Guidance

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2026-11-08 11:08 UTC
September 2026 Patch Tuesday — Complete CVE Reference

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All 633 CVEs from September 2026 Patch Tuesday — searchable, filterable, with plain-English IT admin notes on every vulnerability. Includes CVE - 2026 -81963, the exploited Windows Update Stack EoP, and the five CVEs KB5124008 does not fix .

2026-11-08 11:08 UTC
Security Advisories and Bulletins | Microsoft Learn

web:learn.microsoft.com

In this library you will find the following security documents that have been released by the Microsoft Security Response Center (MSRC). The MSRC investigates all reports of security vulnerabilities affecting Microsoft products and services, and releases these documents as part of the ongoing effort ...

2026-11-08 11:08 UTC
Security Update Guide - Microsoft

web:msrc.microsoft.com

The Microsoft Security Response Center (MSRC) investigates all reports of security vulnerabilities affecting Microsoft products and services, and provides the information here as part of the ongoing effort to help you manage security risks and help keep your systems protected.

2026-11-08 11:08 UTC
Microsoft Patch Tracker (November 2026): Exploit-Ranked | Senserva

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Every Microsoft security patch (KB) and the CVEs it fixes, with severity, CVSS, and CISA KEV status. Cross-linked to the CVE reference.

2026-11-08 11:08 UTC
Microsoft October 2026 Patch Tuesday fixes 1,411 flaws, 3 zero-days

web:www.bleepingcomputer.com

Today is Microsoft's October 2026 Patch Tuesday, with security updates addressing a record-breaking 1,411 flaws, including one actively exploited and two publicly disclosed zero-day vulnerabilities.

2026-11-08 11:08 UTC
September 2026 Patch Tuesday: Updates and Analysis | CrowdStrike

web:www.crowdstrike.com

Microsoft has released security updates for 972 vulnerabilities, including two exploited zero-days and 113 critical, in its September 2026 Patch Tuesday rollout.

2026-11-08 11:08 UTC
Microsoft Shatters Patch Tuesday Record With 974 CVE Fixes in Septembe

web:www.infosecurity-magazine.com

Microsoft has announced fixes for a record 974 CVEs in its September 2026 Patch Tuesday release. The number of flaws included in this month's update shatters the previous record for Patch Tuesday, which was 570 CVEs in July 2026 . The September CVE list spans Microsoft's product portfolio, with ...

2026-11-08 11:08 UTC
Patch Tuesday CVE Analysis, Month by Month - Lansweeper

web:www.lansweeper.com

Monthly Microsoft Patch Tuesday breakdowns: actively exploited CVEs , critical fixes, and what to patch first. Every release analyzed by the Lansweeper team.

2026-11-08 11:08 UTC
Patch Tuesday September 2026: Security Updates & CVE Analysis

web:zecurit.com

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

2026-11-08 11:08 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-99272.json.

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/client/smb2pdu.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "1ba1937de005e261a8858f45bfef5da7458df94c",
              "status": "affected",
              "version": "d8e050398d23ef7c019c96200b80d73f4e5cec0c",
              "versionType": "git"
            },
            {
              "lessThan": "2ec9cdf469dd32bcf33073aeb30c08e9356e0ca1",
              "status": "affected",
              "version": "d8e050398d23ef7c019c96200b80d73f4e5cec0c",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/client/smb2pdu.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.7"
            },
            {
              "lessThan": "3.7",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.3.*",
              "status": "unaffected",
              "version": "7.3.2",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.4-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3.2",
                  "versionStartIncluding": "3.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.4-rc1",
                  "versionStartIncluding": "3.7",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: validate the data area in SMB2_read()\n\nSMB2_read() copies le32_to_cpu(rsp->DataLength) bytes from\n(char *)rsp + rsp->DataOffset without checking that the range lies\nwithin the response actually received. A READ response with\nDataOffset == 0 makes smb2_get_data_area_len() zero the data length, so\nsmb2_check_message() accepts a frame as short as the fixed response,\nwhile SMB2_read() still uses the server-supplied DataLength, capped only\nby CIFS_MAX_MSGSIZE and the caller's length.\n\nA malicious server can answer the synchronous read used by the\nmfsymlinks (or SFU) symlink parser with an 81-byte READ response\ncarrying DataOffset 0 and DataLength 1067, making the client copy 1067\nbytes from a 448-byte receive object (KASAN slab-out-of-bounds; up to\n16 KiB in the general case).\n\nClamp a zero (or header-overlapping) DataOffset to read_rsp_size, as\nhandle_read_data() does for the asynchronous path, and reject the\nresponse unless DataOffset + DataLength fits within rsp_iov.iov_len.\nThe SMB1 helper was fixed the same way in 5be5bdda5863."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-07T14:08:45.332Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/1ba1937de005e261a8858f45bfef5da7458df94c"
        },
        {
          "url": "https://git.kernel.org/stable/c/2ec9cdf469dd32bcf33073aeb30c08e9356e0ca1"
        }
      ],
      "title": "smb: client: validate the data area in SMB2_read()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-99272",
    "datePublished": "2026-11-07T14:08:45.332Z",
    "dateReserved": "2026-09-25T10:25:14.404Z",
    "dateUpdated": "2026-11-07T14:08:45.332Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}