CVE-2026-43066

Description

In the Linux kernel, the following vulnerability has been resolved: ext4: fix iloc.bh leak in ext4_fc_replay_inode() error paths During code review, Joseph found that ext4_fc_replay_inode() calls ext4_get_fc_inode_loc() to get the inode location, which holds a reference to iloc.bh that must be released via brelse(). However, several error paths jump to the 'out' label without releasing iloc.bh: - ext4_handle_dirty_metadata() failure - sync_dirty_buffer() failure - ext4_mark_inode_used() failure - ext4_iget() failure Fix this by introducing an 'out_brelse' label placed just before the existing 'out' label to ensure iloc.bh is always released. Additionally, make ext4_fc_replay_inode() propagate errors properly instead of always returning 0.

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:H/I:N/A:H
Effective score: 7.1 / 10 HIGH source: CNA overview
CWE(s): —
Reserved: 2026-05-01
Published: 2026-05-05 17:23 UTC
Last updated: 2026-05-12 00:17 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/43xxx/CVE-2026-43066.json
Linked Threat: CVE-2026-43066 — CVE-2026-43066

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: 2026-05-05 16:16:15 UTC
NVD last modified: 2026-05-06 13:08:07 UTC
EPSS score: 0.0003 (probability of exploitation in next 30 days)
EPSS percentile: 9.59% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24

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-2026-27365
Assigner: Linux
Published: May 5, 2026, 3:23:25 PM
Updated: May 11, 2026, 10:17:03 PM
EUVD base score: 0.0 / 10
EUVD-reported EPSS: 0.0100
Vendors: Linux
Products: Linux (8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 <0892f12cd49fde5d5db68137923db107f894f3a3)

Linux (patch: 5.10.253)

Linux (8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 <c426231e3d51916e83b6d1ab7ed8a65e83bca5b4)

Linux (patch: 5.15.203)

Linux (patch: 7.0)

Linux (5.10)

Linux (8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 <ec0a7500d8eace5b4f305fa0c594dd148f0e8d29)

Linux (8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 <19782b4c793b49a6aa4abbb307ddff3610009d21)

Linux (patch: 6.6.131)

Linux (patch: 6.19.11)

Linux (patch: 6.12.80)

Linux (8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 <ca99cbcc316cdfd2040cc2b13d1426ccb3b3b50b)

Linux (patch: 6.1.168)

Linux (patch: 6.18.21)

Linux (8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 <9c90449a9ac2cd1ba540ad2561b8b70c1bfb0a25)

Linux (8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 <5a63033696e60b5d70816f1d119645ac5b0b0a03)

Linux (patch: 0)

Linux (8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 <f7817ad399d604e8639005d87d148b5ec626ad26)

ENISA description: In the Linux kernel, the following vulnerability has been resolved: ext4: fix iloc.bh leak in ext4_fc_replay_inode() error paths During code review, Joseph found that ext4_fc_replay_inode() calls ext4_get_fc_inode_loc() to get the inode location, which holds a reference to iloc.bh that must be released via brelse(). However, several error paths jump to the 'out' label without releasing iloc.bh: - ext4_handle_dirty_metadata() failure - sync_dirty_buffer() failure - ext4_mark_inode_used() failure - ext4_iget() failure Fix this by introducing an 'out_brelse' label placed just before the existing 'out' label to ensure iloc.bh is always released. Additionally, make ext4_fc_replay_inode() propagate errors properly instead of always returning 0.

EUVD references (8)

Affected products (2)

Vendor	Product	Versions	Platforms
Linux	Linux	`8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2` (affected), `8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2` (affected), `8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2` (affected), `8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2` (affected), `8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2` (affected), `8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2` (affected), `8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2` (affected), `8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2` (affected)	—
Linux	Linux	`5.10` (affected), `0` (unaffected), `5.10.253` (unaffected), `5.15.203` (unaffected), `6.1.168` (unaffected), `6.6.131` (unaffected), `6.12.80` (unaffected), `6.18.21` (unaffected), `6.19.11` (unaffected), `7.0` (unaffected)	—

Vendor references (8)

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

MITRE references (8) cveawg.mitre.org

Pulled from MITRE's CVE Services API by the 🛰 Backfill from MITRE button.

Web references (6)

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

http://iloc.bh rapid7:iloc.bh
https://attackerkb.com/topics/CVE-2026-43066 rapid7:attackerkb.com
https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-27365 rapid7:euvd.enisa.europa.eu
https://www.first.org/epss/ tenable:www.first.org
https://nvd.nist.gov/vuln/detail/CVE-2026-43066 tenable:nvd.nist.gov
https://www.cve.org/CVERecord?id=CVE-2026-43066 tenable:www.cve.org

NVD-tagged references (8)

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/0892f12cd49fde5d5db68137923db107f894f3a3 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/19782b4c793b49a6aa4abbb307ddff3610009d21 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/5a63033696e60b5d70816f1d119645ac5b0b0a03 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/9c90449a9ac2cd1ba540ad2561b8b70c1bfb0a25 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/c426231e3d51916e83b6d1ab7ed8a65e83bca5b4 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/ca99cbcc316cdfd2040cc2b13d1426ccb3b3b50b 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/ec0a7500d8eace5b4f305fa0c594dd148f0e8d29 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/f7817ad399d604e8639005d87d148b5ec626ad26 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Remediations (15)

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

Microsoft and Adobe Patch Tuesday, April 2026 Security Update Review

web:blog.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.

2026-05-23 21:13 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?

2026-05-23 21:13 UTC
Nvd - Cve-2026-43660

web:nvd.nist.gov

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

2026-05-23 21:13 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.

2026-05-23 21:13 UTC
Critical Patches Issued for Microsoft Products, April 14, 2026

web:www.cisecurity.org

<p>Multiple vulnerabilities have been discovered in Microsoft products, the most severe of which could allow for remote code execution. Successful exploitation of the most severe of these vulnerabilities could result in an attacker gaining the same privileges as the logged-on user. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or ...

2026-05-23 21:13 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.

2026-05-23 21:13 UTC
Microsoft April 2026 Patch Tuesday fixes 167 ... - Notebookcheck

web:www.notebookcheck.net

Microsoft April 2026 Patch Tuesday fixes 167 vulnerabilities, including an actively exploited SharePoint zero-day. Windows 11 KB5083769 and KB5082052 bring new builds and RDP security.

2026-05-23 21:13 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.

2026-05-23 21:13 UTC
Microsoft Issues Massive Windows Patch for 160+ Bugs ... - TechRepublic

web:www.techrepublic.com

Microsoft's April 2026 Patch Tuesday fixes 165 vulnerabilities, including two zero-days, in one of the company's largest monthly security updates.

2026-05-23 21:13 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.

2026-05-23 21:13 UTC
THREAT ADVISORY RedSun Zero-Day (Windows Defender) April 17, 2026

web:blackswan-cybersecurity.com

Cloud Files API activity originating outside legitimate OneDrive/sync processes. Mitigation Steps: Apply all Windows updates immediately (monitor MSRC for an emergency RedSun-specific patch . None released as of April 17, 2026 ). Supplement Defender with a secondary EDR solution (e.g., Huntress) capable of detecting Defender bypasses.

2026-06-03 07:49 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 07:49 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.

2026-06-03 07:49 UTC
Nvd - Cve-2025-53066

web:nvd.nist.gov

An official website of the United States government NVD MENU

2026-06-03 07:49 UTC
Windows 11 KB5083769 update triggers BitLocker recovery | Windows Central

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 07:49 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-43066.json.

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          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix iloc.bh leak in ext4_fc_replay_inode() error paths\n\nDuring code review, Joseph found that ext4_fc_replay_inode() calls\next4_get_fc_inode_loc() to get the inode location, which holds a\nreference to iloc.bh that must be released via brelse().\n\nHowever, several error paths jump to the 'out' label without\nreleasing iloc.bh:\n\n - ext4_handle_dirty_metadata() failure\n - sync_dirty_buffer() failure\n - ext4_mark_inode_used() failure\n - ext4_iget() failure\n\nFix this by introducing an 'out_brelse' label placed just before\nthe existing 'out' label to ensure iloc.bh is always released.\n\nAdditionally, make ext4_fc_replay_inode() propagate errors\nproperly instead of always returning 0."
        }
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      "providerMetadata": {
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        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
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        {
          "url": "https://git.kernel.org/stable/c/ec0a7500d8eace5b4f305fa0c594dd148f0e8d29"
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      ],
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  "cveMetadata": {
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    "cveId": "CVE-2026-43066",
    "datePublished": "2026-05-05T15:23:25.984Z",
    "dateReserved": "2026-05-01T14:12:55.981Z",
    "dateUpdated": "2026-05-11T22:17:03.438Z",
    "state": "PUBLISHED"
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