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CVE-2026-43499

📛 CVE Title

rtmutex: Use waiter::task instead of current in remove_waiter()

⬇ Download JSON ⚠ View as Threat

Description

In the Linux kernel, the following vulnerability has been resolved: rtmutex: Use waiter::task instead of current in remove_waiter() remove_waiter() is used by the slowlock paths, but it is also used for proxy-lock rollback in rt_mutex_start_proxy_lock() when invoked from futex_requeue(). In the latter case waiter::task is not current, but remove_waiter() operates on current for the dequeue operation. That results in several problems: 1) the rbtree dequeue happens without waiter::task::pi_lock being held 2) the waiter task's pi_blocked_on state is not cleared, which leaves a dangling pointer primed for UAF around. 3) rt_mutex_adjust_prio_chain() operates on the wrong top priority waiter task Use waiter::task instead of current in all related operations in remove_waiter() to cure those problems. [ tglx: Fixup rt_mutex_adjust_prio_chain(), add a comment and amend the changelog ]

Overview

State
PUBLISHED
Assigner (CNA)
Linux
CVSS severity
high
CVSS score
CVSS 7.8 / 10 7.8 7.8 / 10
CVSS vector
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Effective score
7.8 / 10 HIGH source: CNA overview
MSRC score
7.8 / 10 HIGH MS rating: Important
CWE(s)
—
Reserved
2026-05-01
Published
2026-05-21 12:17 UTC
Last updated
2026-05-21 12:17 UTC
Source
https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/43xxx/CVE-2026-43499.json
Linked Threat
CVE-2026-43499 — CVE-2026-43499

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
7.22% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24

NVD / KEV / EPSS data refreshed 2026-05-25 00:28 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-2026-31277
Assigner
Linux
Published
May 21, 2026, 12:17:49 PM
Updated
May 30, 2026, 10:45:19 AM
EUVD base score (CVSS 3.1)
7.8 / 10
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EUVD-reported EPSS
0.0100
Vendors
Linux
Products
Linux (patch: 6.12.86)
Linux (patch: 0)
Linux (patch: 6.18.27)
Linux (patch: 6.6.140)
Linux (patch: 7.1-rc1)
Linux (patch: 7.0.4)
Linux (8161239a8bcce9ad6b537c04a1fa3b5c68bae693 <8a1fc8d698ac5e5916e3082a0f74450d71f9611f)
Linux (8161239a8bcce9ad6b537c04a1fa3b5c68bae693 <6d52dfcb2a5db86e346cf51f8fcf2071b8085166)
Linux (8161239a8bcce9ad6b537c04a1fa3b5c68bae693 <3fb7394a837740770f0d6b4b30567e60786a63f2)
Linux (8161239a8bcce9ad6b537c04a1fa3b5c68bae693 <3bfdc63936dd4773109b7b8c280c0f3b5ae7d349)
Linux (8161239a8bcce9ad6b537c04a1fa3b5c68bae693 <88614876370aac8ad1050ad785a4c095ba17ac11)
Linux (2.6.39)
Aliases
GHSA-cqc6-9f34-295v

ENISA description: In the Linux kernel, the following vulnerability has been resolved: rtmutex: Use waiter::task instead of current in remove_waiter() remove_waiter() is used by the slowlock paths, but it is also used for proxy-lock rollback in rt_mutex_start_proxy_lock() when invoked from futex_requeue(). In the latter case waiter::task is not current, but remove_waiter() operates on current for the dequeue operation. That results in several problems: 1) the rbtree dequeue happens without waiter::task::pi_lock being held 2) the waiter task's pi_blocked_on state is not cleared, which leaves a dangling pointer primed for UAF around. 3) rt_mutex_adjust_prio_chain() operates on the wrong top priority waiter task Use waiter::task instead of current in all related operations in remove_waiter() to cure those problems. [ tglx: Fixup rt_mutex_adjust_prio_chain(), add a comment and amend the changelog ]

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 8161239a8bcce9ad6b537c04a1fa3b5c68bae693 (affected), 8161239a8bcce9ad6b537c04a1fa3b5c68bae693 (affected), 8161239a8bcce9ad6b537c04a1fa3b5c68bae693 (affected), 8161239a8bcce9ad6b537c04a1fa3b5c68bae693 (affected), 8161239a8bcce9ad6b537c04a1fa3b5c68bae693 (affected) —
Linux Linux 2.6.39 (affected), 0 (unaffected), 6.6.140 (unaffected), 6.12.86 (unaffected), 6.18.27 (unaffected), 7.0.4 (unaffected), 7.1-rc1 (unaffected) —

Vendor references (5)

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

Web references (11)

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 (17)

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

  • Microsoft and Adobe Patch Tuesday, February 2026 Security Update Review
    web:blog.qualys.com

    Microsoft's February 2026 Patch Tuesday focuses on closing security gaps that attackers could exploit, reinforcing the importance of timely patching in enterprise environments. Here's a quick…

    2026-05-24 12:02 UTC
  • 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
  • Patch Tuesday, April 2026 Edition - Krebs on Security
    web:krebsonsecurity.com

    For a clickable, per- patch breakdown, check out the SANS Internet Storm Center Patch Tuesday roundup. Running into problems applying any of these updates?

    2026-05-24 12:02 UTC
  • Nvd - Cve-2026-43499
    web:nvd.nist.gov

    Description In the Linux kernel, the following vulnerability has been resolved: rtmutex: Use waiter::task instead of current in remove_waiter () remove_waiter () is used by the slowlock paths, but it is also used for proxy-lock rollback in rt_mutex_start_proxy_lock () when invoked from futex_requeue (). In the latter case waiter::task is not current, but remove_waiter () operates on current ...

    2026-05-24 12:02 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.

    2026-05-24 12:02 UTC
  • Emergency patch issued for Microsoft Office, 365 over hacking threat - MSN
    web:www.msn.com

    Microsoft suggests the threat is being used in phishing attacks against vulnerable systems since successful exploitation requires local access to the PC.

    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
  • Patch Tuesday May 2026: Security Updates & CVE Analysis
    web:zecurit.com

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

    2026-05-24 12:02 UTC
  • Microsoft Patch Tuesday April 2026 - 168 Vulnerabilities Fixed ...
    web:cybersecuritynews.com

    Microsoft has released its April 2026 Patch Tuesday security update, addressing 168 vulnerabilities across its product portfolio including one actively exploited zero-day and one publicly disclosed flaw that organizations must prioritize immediately.

    2026-06-03 22:32 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
  • Windows 11, version 25H2 known issues and notifications
    web:learn.microsoft.com

    Windows 11, version 25H2 is now available for all eligible devices. Devices running Home and Pro editions of Windows 11 that are not managed by IT departments will receive the update to Windows 11, version 25H2 through the machine learning-based intelligent rollout.

    2026-06-03 22:32 UTC
  • Windows 11 Update KB5083769: Download link, new features & fixes ...
    web:thewincentral.com

    Microsoft rolls out Windows 11 KB5083769 (April 2026 update). New features & fixes. How to download. - Read in Latest News on WinCentral

    2026-06-03 22:32 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.

    2026-06-03 22:32 UTC
  • Windows 11 KB5083769 April 2026 update triggers death loops and BSODs
    web:www.notebookcheck.net

    Microsoft's Windows 11 KB5083769 April 2026 update causes critical boot failures, pixelated BSODs, and BitLocker recovery loops on Windows 11 24H2 and 25H2 PCs.

    2026-06-03 22:32 UTC
  • "This update broke BitLocker for me" — Windows 11's April patch is ...
    web:www.windowscentral.com

    A faulty BitLocker configuration is forcing some PCs into BitLocker recovery mode after the April 2026 update, but there's a workaround to resolve this issue.

    2026-06-03 22:32 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-43499.json.

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          "programFiles": [
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              "lessThanOrEqual": "*",
              "status": "unaffected",
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        }
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        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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    "dateReserved": "2026-05-01T14:12:56.014Z",
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