CVE-2026-43458

Description

In the Linux kernel, the following vulnerability has been resolved: serial: caif: hold tty->link reference in ldisc_open and ser_release A reproducer triggers a KASAN slab-use-after-free in pty_write_room() when caif_serial's TX path calls tty_write_room(). The faulting access is on tty->link->port. Hold an extra kref on tty->link for the lifetime of the caif_serial line discipline: get it in ldisc_open() and drop it in ser_release(), and also drop it on the ldisc_open() error path. With this change applied, the reproducer no longer triggers the UAF in my testing.

Overview

State: PUBLISHED
Assigner (CNA): Linux
CVSS severity: high
CVSS score: 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
CWE(s): —
Reserved: 2026-05-01
Published: 2026-05-08 16:22 UTC
Last updated: 2026-05-12 00:24 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/43xxx/CVE-2026-43458.json
Linked Threat: CVE-2026-43458 — CVE-2026-43458

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: 2026-05-08 15:16:58 UTC
NVD last modified: 2026-05-21 16:47:42 UTC
NVD CVSS v3.1: 7.8 / 10 HIGH source: nvd@nist.gov
NVD CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Exploitability subscore: 1.8 / 10
Impact subscore: 5.9 / 10
EPSS score: 0.0001 (probability of exploitation in next 30 days)
EPSS percentile: 2.55% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24

NVD-assigned CWE(s): CWE-416 (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-2026-28764
Assigner: Linux
Published: May 8, 2026, 2:22:21 PM
Updated: May 11, 2026, 10:24:58 PM
EUVD base score: 0.0 / 10
EUVD-reported EPSS: 0.0100
Vendors: Linux
Products: Linux (e31d5a05948e4478ba8396063d1e1f39880928e2 <97a0bb491cae39478c6225381f14e9ac67b7bba7)

Linux (e31d5a05948e4478ba8396063d1e1f39880928e2 <8460187b4852fd00bd1c76394358053f3fa4d089)

Linux (patch: 7.0)

Linux (patch: 5.15.203)

Linux (e31d5a05948e4478ba8396063d1e1f39880928e2 <35b58d3bc716ebb9ebd10fe1cac8c1177242511c)

Linux (patch: 0)

Linux (patch: 6.12.78)

Linux (patch: 6.18.19)

Linux (e31d5a05948e4478ba8396063d1e1f39880928e2 <ca2ceba983bb23ea0202c2882d963253416654a3)

Linux (e31d5a05948e4478ba8396063d1e1f39880928e2 <27e43356d0defb9fc7fa25265219a3ffeb7b3e98)

Linux (patch: 5.10.253)

Linux (patch: 6.1.167)

Linux (2.6.35)

Linux (e31d5a05948e4478ba8396063d1e1f39880928e2 <288598d80a068a0e9281de35bcb4ce495f189e2a)

Linux (e31d5a05948e4478ba8396063d1e1f39880928e2 <23a3ac2e2262a291498567418227b99e1f3606b1)

Linux (patch: 6.6.130)

Linux (e31d5a05948e4478ba8396063d1e1f39880928e2 <52135420e9f75853ea0c6cea7b736e3e98495f7d)

Linux (patch: 6.19.9)

ENISA description: In the Linux kernel, the following vulnerability has been resolved: serial: caif: hold tty->link reference in ldisc_open and ser_release A reproducer triggers a KASAN slab-use-after-free in pty_write_room() when caif_serial's TX path calls tty_write_room(). The faulting access is on tty->link->port. Hold an extra kref on tty->link for the lifetime of the caif_serial line discipline: get it in ldisc_open() and drop it in ser_release(), and also drop it on the ldisc_open() error path. With this change applied, the reproducer no longer triggers the UAF in my testing.

EUVD references (8)

Affected products (2)

Vendor	Product	Versions	Platforms
Linux	Linux	`e31d5a05948e4478ba8396063d1e1f39880928e2` (affected), `e31d5a05948e4478ba8396063d1e1f39880928e2` (affected), `e31d5a05948e4478ba8396063d1e1f39880928e2` (affected), `e31d5a05948e4478ba8396063d1e1f39880928e2` (affected), `e31d5a05948e4478ba8396063d1e1f39880928e2` (affected), `e31d5a05948e4478ba8396063d1e1f39880928e2` (affected), `e31d5a05948e4478ba8396063d1e1f39880928e2` (affected), `e31d5a05948e4478ba8396063d1e1f39880928e2` (affected)	—
Linux	Linux	`2.6.35` (affected), `0` (unaffected), `5.10.253` (unaffected), `5.15.203` (unaffected), `6.1.167` (unaffected), `6.6.130` (unaffected), `6.12.78` (unaffected), `6.18.19` (unaffected), `6.19.9` (unaffected), `7.0` (unaffected)	—

Affected products — CPE 2.3 (4) 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:7.0:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*

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://cwe.mitre.org/data/definitions/416.html rapid7:cwe.mitre.org
https://attackerkb.com/topics/CVE-2026-43458 rapid7:attackerkb.com
https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-28764 rapid7:euvd.enisa.europa.eu
https://www.first.org/epss/ tenable:www.first.org
https://nvd.nist.gov/vuln/detail/CVE-2026-43458 tenable:nvd.nist.gov
https://www.cve.org/CVERecord?id=CVE-2026-43458 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/23a3ac2e2262a291498567418227b99e1f3606b1 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/27e43356d0defb9fc7fa25265219a3ffeb7b3e98 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/288598d80a068a0e9281de35bcb4ce495f189e2a 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/35b58d3bc716ebb9ebd10fe1cac8c1177242511c 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/52135420e9f75853ea0c6cea7b736e3e98495f7d 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/8460187b4852fd00bd1c76394358053f3fa4d089 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/97a0bb491cae39478c6225381f14e9ac67b7bba7 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch
https://git.kernel.org/stable/c/ca2ceba983bb23ea0202c2882d963253416654a3 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Patch

Remediations (18)

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

Microsoft Patch Tuesday for May 2026 — Snort rules and prominent ...

web:blog.talosintelligence.com

Microsoft has released its monthly security update for May 2026 , which includes 137 vulnerabilities affecting a range of products, including 16 that Microsoft marked as "critical".

2026-05-23 21:04 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 .

2026-05-23 21:04 UTC
Patch Tuesday, May 2026 Edition - Krebs on Security

web:krebsonsecurity.com

Microsoft expects that exploitation is more likely. May's Patch Tuesday is a welcome respite from April, which saw Microsoft fix a near-record 167 security flaws.

2026-05-23 21:04 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.

2026-05-23 21:04 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 21:04 UTC
CISA orders feds to patch exploited Fortinet EMS flaw by Friday

web:www.bleepingcomputer.com

On Monday, CISA added CVE - 2026 -35616 to its Known Exploited Vulnerabilities (KEV) Catalog and ordered Federal Civilian Executive Branch (FCEB) agencies to patch FortiClient EMS instances by ...

2026-05-23 21:04 UTC
Fortinet Releases Guidance to Address Ongoing Exploitation of ... - CISA

web:www.cisa.gov

Fortinet Releases Guidance to Address Ongoing Exploitation of Authentication Bypass Vulnerability CVE - 2026 -24858

2026-05-23 21:04 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 21:04 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 21:04 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 .

2026-05-23 21:04 UTC
Windows Kerberos RC4 deprecation: what will break in Active ... - 4sysops

web:4sysops.com

Starting in April 2026 , Windows updates will change the default Kerberos ticket issuance behavior to AES-SHA1 for accounts without explicit encryption settings, while RC4 can still be used where explicitly enabled. This change, driven by CVE - 2026 -20833, affects every Windows Server environment where service accounts or devices still rely on RC4. Any service account, NAS device, or legacy ...

2026-05-26 02:47 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 ...

2026-05-26 02:47 UTC
Microsoft is aware of a security feature bypass... · CVE-2026 ... - GitHub

web:github.com

Microsoft is aware of a security feature bypass vulnerability in Windows publicly referred to as "YellowKey". The proof of concept for this vulnerability has been made public violating coordinated vulnerability best practices. We are issuing this CVE to provide mitigation guidance that can be implemented to protect against this vulnerability until the security update is made available ...

2026-05-26 02:47 UTC
Security Update Guide - Loading - Microsoft

web:msrc.microsoft.com

Security Updates Acknowledgements

2026-05-26 02:47 UTC
Nvd - Cve-2026-45585

web:nvd.nist.gov

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

2026-05-26 02:47 UTC
How To Scan & Fix The Log4j Vulnerability - PurpleSec

web:purplesec.us

Discover how to scan for and fix Log4j vulnerabilities, ensuring the security of your Java applications while continuing to benefit from this widely-used logging library.

2026-05-26 02:47 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 ...

2026-05-26 02:47 UTC
Microsoft Patches 138 Vulnerabilities, Including DNS and Netlogon RCE Flaws

web:thehackernews.com

Microsoft patched 138 flaws, including 30 Critical bugs, as AI discovery expands Patch Tuesday risk.

2026-05-26 02:47 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-43458.json.

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/caif/caif_serial.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
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              "status": "affected",
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              "versionType": "git"
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            {
              "lessThan": "ca2ceba983bb23ea0202c2882d963253416654a3",
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            {
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          ],
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          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.35"
            },
            {
              "lessThan": "2.6.35",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.253",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.203",
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            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.167",
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            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.130",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.78",
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            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.19",
              "versionType": "semver"
            },
            {
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              "status": "unaffected",
              "version": "6.19.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
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          "nodes": [
            {
              "cpeMatch": [
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                  "versionStartIncluding": "2.6.35",
                  "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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                  "versionStartIncluding": "2.6.35",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "versionStartIncluding": "2.6.35",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nserial: caif: hold tty->link reference in ldisc_open and ser_release\n\nA reproducer triggers a KASAN slab-use-after-free in pty_write_room()\nwhen caif_serial's TX path calls tty_write_room(). The faulting access\nis on tty->link->port.\n\nHold an extra kref on tty->link for the lifetime of the caif_serial line\ndiscipline: get it in ldisc_open() and drop it in ser_release(), and\nalso drop it on the ldisc_open() error path.\n\nWith this change applied, the reproducer no longer triggers the UAF in\nmy testing."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T22:24:58.635Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/23a3ac2e2262a291498567418227b99e1f3606b1"
        },
        {
          "url": "https://git.kernel.org/stable/c/52135420e9f75853ea0c6cea7b736e3e98495f7d"
        },
        {
          "url": "https://git.kernel.org/stable/c/ca2ceba983bb23ea0202c2882d963253416654a3"
        },
        {
          "url": "https://git.kernel.org/stable/c/8460187b4852fd00bd1c76394358053f3fa4d089"
        },
        {
          "url": "https://git.kernel.org/stable/c/27e43356d0defb9fc7fa25265219a3ffeb7b3e98"
        },
        {
          "url": "https://git.kernel.org/stable/c/35b58d3bc716ebb9ebd10fe1cac8c1177242511c"
        },
        {
          "url": "https://git.kernel.org/stable/c/97a0bb491cae39478c6225381f14e9ac67b7bba7"
        },
        {
          "url": "https://git.kernel.org/stable/c/288598d80a068a0e9281de35bcb4ce495f189e2a"
        }
      ],
      "title": "serial: caif: hold tty->link reference in ldisc_open and ser_release",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-43458",
    "datePublished": "2026-05-08T14:22:21.997Z",
    "dateReserved": "2026-05-01T14:12:56.010Z",
    "dateUpdated": "2026-05-11T22:24:58.635Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}