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CVE-2026-43497

📛 CVE Title

fbdev: udlfb: add vm_ops to dlfb_ops_mmap to prevent use-after-free

⬇ Download JSON ⚠ View as Threat

Description

In the Linux kernel, the following vulnerability has been resolved: fbdev: udlfb: add vm_ops to dlfb_ops_mmap to prevent use-after-free dlfb_ops_mmap() uses remap_pfn_range() to map vmalloc framebuffer pages to userspace but sets no vm_ops on the VMA. This means the kernel cannot track active mmaps. When dlfb_realloc_framebuffer() replaces the backing buffer via FBIOPUT_VSCREENINFO, existing mmap PTEs are not invalidated. On USB disconnect, dlfb_ops_destroy() calls vfree() on the old pages while userspace PTEs still reference them, resulting in a use-after-free: the process retains read/write access to freed kernel pages. Add vm_operations_struct with open/close callbacks that maintain an atomic mmap_count on struct dlfb_data. In dlfb_realloc_framebuffer(), check mmap_count and return -EBUSY if the buffer is currently mapped, preventing buffer replacement while userspace holds stale PTEs. Tested with PoC using dummy_hcd + raw_gadget USB device emulation.

Overview

State
PUBLISHED
Assigner (CNA)
Linux
CVSS severity
high
CVSS score
CVSS 7.3 / 10 7.3 7.3 / 10
CVSS vector
AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
Effective score
7.3 / 10 HIGH source: CNA overview
MSRC score
7.8 / 10 HIGH MS rating: Important
CWE(s)
—
Reserved
2026-05-01
Published
2026-05-21 12:12 UTC
Last updated
2026-05-22 07:32 UTC
Source
https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/43xxx/CVE-2026-43497.json
Linked Threat
CVE-2026-43497 — CVE-2026-43497

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
2026-05-21 13:16:19 UTC
NVD last modified
2026-05-21 13:16:19 UTC
EPSS score
0.0002 (probability of exploitation in next 30 days)
EPSS percentile
5.07% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24

NVD / KEV / EPSS data refreshed 2026-05-25 00:26 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.

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-2026-31273
Assigner
Linux
Published
May 21, 2026, 12:12:47 PM
Updated
May 30, 2026, 10:45:14 AM
EUVD base score (CVSS 3.1)
7.3 / 10
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
EUVD-reported EPSS
0.0100
Vendors
Linux
Products
Linux (4.19)
Linux (1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <da9b065cedfd3b574f229d5be594e6aa47a27ae6)
Linux (patch: 0)
Linux (1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8de779dc40d35d39fa07387b6f921eb11df0f511)
Linux (7433914efd584b22bb49d3e1eee001f5d0525ecd <da9b065cedfd3b574f229d5be594e6aa47a27ae6)
Linux (patch: 7.1-rc3)
Linux (patch: 6.6.140)
Linux (patch: 6.18.30)
Linux (7433914efd584b22bb49d3e1eee001f5d0525ecd <8de779dc40d35d39fa07387b6f921eb11df0f511)
Linux (1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a2c53a3822ee26e8d758071815b9ed3bf6669fc1)
Linux (patch: 6.12.88)
Linux (7433914efd584b22bb49d3e1eee001f5d0525ecd <4f312c30f0368e8d2a76aa650dff73f23490b5e7)
Linux (7433914efd584b22bb49d3e1eee001f5d0525ecd <18dd358de72d57993422cbb5dfb29ccd74efe192)
Linux (1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4f312c30f0368e8d2a76aa650dff73f23490b5e7)
Linux (1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <18dd358de72d57993422cbb5dfb29ccd74efe192)
Linux (patch: 7.0.7)
Linux (7433914efd584b22bb49d3e1eee001f5d0525ecd <a2c53a3822ee26e8d758071815b9ed3bf6669fc1)
Aliases
GHSA-233x-r9gj-mfg9

ENISA description: In the Linux kernel, the following vulnerability has been resolved: fbdev: udlfb: add vm_ops to dlfb_ops_mmap to prevent use-after-free dlfb_ops_mmap() uses remap_pfn_range() to map vmalloc framebuffer pages to userspace but sets no vm_ops on the VMA. This means the kernel cannot track active mmaps. When dlfb_realloc_framebuffer() replaces the backing buffer via FBIOPUT_VSCREENINFO, existing mmap PTEs are not invalidated. On USB disconnect, dlfb_ops_destroy() calls vfree() on the old pages while userspace PTEs still reference them, resulting in a use-after-free: the process retains read/write access to freed kernel pages. Add vm_operations_struct with open/close callbacks that maintain an atomic mmap_count on struct dlfb_data. In dlfb_realloc_framebuffer(), check mmap_count and return -EBUSY if the buffer is currently mapped, preventing buffer replacement while userspace holds stale PTEs. Tested with PoC using dummy_hcd + raw_gadget USB device emulation.

EUVD references (5)

Microsoft Security Response Center MSRC

Microsoft's vendor-authoritative record from the Security Update Guide — its own CVSS score, impact, severity rating, exploit assessment, and KB-article fixes. Refreshed 2026-08-12 01:09 UTC (source: CVRF).

MS severity
Important
MS CVSS base score
7.8 / 10 (temporal 7.1)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U
Release
2026-May
Microsoft remediations / KB articles (2)

Affected products (2)
VendorProductVersionsPlatforms
Linux Linux 7433914efd584b22bb49d3e1eee001f5d0525ecd (affected), 7433914efd584b22bb49d3e1eee001f5d0525ecd (affected), 7433914efd584b22bb49d3e1eee001f5d0525ecd (affected), 7433914efd584b22bb49d3e1eee001f5d0525ecd (affected), 7433914efd584b22bb49d3e1eee001f5d0525ecd (affected) —
Linux Linux 4.19 (affected), 0 (unaffected), 6.6.140 (unaffected), 6.12.88 (unaffected), 6.18.30 (unaffected), 7.0.7 (unaffected), 7.1-rc3 (unaffected) —

Vendor references (5)

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

Web references (13)

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

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.

Remediations (20)

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

  • Security Advisory Bulletin 064 | Ubiquiti Community
    web:community.ui.com

    Published: May 21, 2026 Updated: May 22, 2026 Version: 1.1 Revision: 1.1 Summary 1 of 5 A malicious actor with access to the network and high privileges could exploit an Improper Input Validation vulnerability found in UniFi OS devices to execute a Command Injection. Affected Products: UniFi OS Server (Version 5.0.6 and earlier) Mitigation : Update your UniFi OS Server to Version 5.0.8 or later ...

    2026-05-24 12:02 UTC
  • CISA Warns of Exploited Microsoft Defender 0-Day Flaws
    web:cyberpress.org

    The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added two actively exploited Microsoft Defender vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog, issuing an urgent remediation directive for federal agencies with a due date of June 3, 2026 .

    2026-05-24 12:02 UTC
  • Security updates for Adobe Acrobat and Reader
    web:helpx.adobe.com

    Security updates for Adobe Acrobat and Reader Last updated on Apr 14, 2026 | Also applies to Adobe Acrobat

    2026-05-24 12:02 UTC
  • Security Update Guide - Microsoft Security Response Center
    web:msrc.microsoft.com

    Security Update Guide - Microsoft Security Response Center

    2026-05-24 12:02 UTC
  • Nvd - Cve-2026-43493
    web:nvd.nist.gov

    An official website of the United States government Here's how you know

    2026-05-24 12:02 UTC
  • How to Use Known Issue Rollback to Fix Problems Caused by Windows ...
    web:petri.com

    If a Group Policy setting is available to roll back a fix , it is included in the Windows Update KB article and release notes as a mitigation for a known issue.

    2026-05-24 12:02 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 ...

    2026-05-24 12:02 UTC
  • April 2026 Patch Tuesday: Updates and Analysis | CrowdStrike
    web:www.crowdstrike.com

    Microsoft's April 2026 Patch Tuesday addresses 164 CVEs , featuring 8 Critical vulnerabilities, one exploited zero-day, and one disclosed zero-day.

    2026-05-24 12:02 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.

    2026-05-24 12:02 UTC
  • Windows 11 April 2026 Update tested: What's new, improved and fixed
    web:www.windowslatest.com

    Windows 11 April 2026 update adds Narrator Copilot support, faster Settings, File Explorer fixes, and key security improvements.

    2026-05-24 12:02 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.

    2026-06-03 22:32 UTC
  • Nvd - Cve-2026-41097
    web:nvd.nist.gov

    This is a potential security issue, you are being redirected to https://nvd.nist.gov

    2026-06-03 22:32 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.

    2026-06-03 22:32 UTC
  • Addressing Exchange Server May 2026 vulnerability CVE-2026-42897
    web:techcommunity.microsoft.com

    Hi team, Our organization has successfully implemented the recommended mitigation for CVE - 2026 -42897. However, we are currently experiencing the documented known issues within our environment. Could the Exchange team kindly provide a tentative timeline or ETA for a permanent security update that resolves the underlying vulnerability while addressing these known issues? We would greatly ...

    2026-06-03 22:32 UTC
  • Microsoft Exchange Server Spoofing Vulnerability Exploited in Attack ...
    web:threatprotect.qualys.com

    With Qualys Policy Audit's out-of-the-box mitigation or Compensatory Controls, which reduce the risk of a vulnerability being exploited because the remediation ( fix / patch ) cannot be done immediately, these security controls are not recommended by any industry standards, such as CIS and DISA-STIG.

    2026-06-03 22:32 UTC
  • CVE-2026-42897 Exchange OWA Mitigation M2: What Admins Must Verify
    web:windowsforum.com

    Microsoft's Fastest Fix Is a Mitigation , Not a Patch The important detail in Microsoft's May 14 notice is that there is no permanent Exchange security update available yet for CVE - 2026 -42897.

    2026-06-03 22:32 UTC
  • Microsoft Confirms Active 0-Day Exploit—Check Emergency Mitigation
    web:www.forbes.com

    Updated May 18: This article has been updated to include further details on the emergency mitigation process recommended by Microsoft after the CVE - 2026 -42897 Exchange Server zero-day was ...

    2026-06-03 22:32 UTC
  • Unpatched Microsoft Exchange Server vulnerability exploited (CVE-2026 ...
    web:www.helpnetsecurity.com

    A critical XSS vulnerability ( CVE - 2026 -42897) in Microsoft Exchange Server is being exploited by attackers, Microsoft warned on Thursday.

    2026-06-03 22:32 UTC
  • Exchange Server OWA Zero-Day CVE-2026-42897 Exploited With No Permanent ...
    web:www.techtimes.com

    Exchange Server OWA Zero-Day CVE - 2026 -42897 Exploited With No Permanent Patch and New Mitigation Gaps Microsoft's emergency fix for on-premises Exchange breaks OWA calendar printing and leaves ...

    2026-06-03 22:32 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 .

    2026-06-03 22:32 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-43497.json.

{
  "containers": {
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              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.30",
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            },
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              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
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              "versionType": "original_commit_for_fix"
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          ]
        }
      ],
      "cpeApplicability": [
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        {
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      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-22T07:32:48.345Z",
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        {
          "url": "https://git.kernel.org/stable/c/8de779dc40d35d39fa07387b6f921eb11df0f511"
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      "title": "fbdev: udlfb: add vm_ops to dlfb_ops_mmap to prevent use-after-free",
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-43497",
    "datePublished": "2026-05-21T12:12:47.150Z",
    "dateReserved": "2026-05-01T14:12:56.013Z",
    "dateUpdated": "2026-05-22T07:32:48.345Z",
    "state": "PUBLISHED"
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