CVE-2026-43499VulnerabilityPublished 24 Aug 2026Updated 5 Nov 2026

Red Hat Security Advisory: kpatch-patch-4_18_0-477_107_1, kpatch-patch-4_18_0-477_120_1

Affects Red HatSource GCVE Database

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Mentioned vulnerabilities

Not known to be exploited.

Data as of 5 Nov 2026, 21:18 UTC

Severity

High

Rated by Threat Radar · CVSS not yet scored by NVD

Exploitation evidence

Disclosed: evidence found.
CVE published 24 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

Red Hat has released official live patch modules for the affected kernel version 4.18.0-477.97.1.el8_8 and related variants. Applying these kpatch live patches will remediate the vulnerabilities without requiring a system reboot. Users should follow Red Hat's update instructions at https://access.redhat.com/articles/11258 to apply the patches promptly. Since this is an official fix, no additional mitigation steps are required beyond applying the update.

Description

Red Hat has issued a security advisory for a kernel live patch module targeting kernel-4.18.0-477.97.1.el8_8. The update addresses four security vulnerabilities in the kernel related to real-time mutex handling, GFS2 filesystem use-after-free, XFRM state list management, and SCTP message sending. These vulnerabilities are identified as CVE-2026-43499, CVE-2026-45984, CVE-2026-46116, and CVE-2026-46227. The advisory rates the security impact as Important and provides updated packages for Red Hat Enterprise Linux 8.8 variants. The patch is available as a live kernel patch module that can be applied without rebooting the system.

Impact

The vulnerabilities fixed by this advisory could lead to kernel instability or security issues such as use-after-free conditions and improper state handling in kernel subsystems (rtmutex, GFS2 filesystem, XFRM networking, SCTP protocol). These issues could potentially be exploited to cause denial of service or other unintended kernel behavior. The advisory rates the impact as Important, indicating a high severity but not critical. There is no indication of known exploits in the wild at this time.

Summary

This Red Hat security advisory covers a kernel live patch module for Red Hat Enterprise Linux 8.8 that fixes four vulnerabilities in the 4.18.0-477 kernel series. The vulnerabilities include a real-time mutex issue where waiter::task is used instead of current in remove_waiter (CVE-2026-43499), a use-after-free flaw in the GFS2 iomap inline data write path (CVE-2026-45984), defensive unhashing of xfrm_state lists to prevent potential issues in __xfrm_state_delete (CVE-2026-46116), and a SCTP protocol fix to revalidate list cursors after sending messages in SCTP_SENDALL (CVE-2026-46227). These fixes are delivered via kpatch live patch modules, allowing modification of running kernel code without downtime. The advisory includes references to Red Hat's errata and update instructions.

CWE-825Expired Pointer Dereference (opens in a new tab)
Base weakness
The product dereferences a pointer that contains a location for memory that was previously valid, but is no longer valid.
Architecture and Design
Choose a language that provides automatic memory management.
Implementation
When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-826Premature Release of Resource During Expected Lifetime (opens in a new tab)
Base weakness
The product releases a resource that is still intended to be used by itself or another actor.
CWE-763Release of Invalid Pointer or Reference (opens in a new tab)
Base weakness
The product attempts to return a memory resource to the system, but it calls the wrong release function or calls the appropriate release function incorrectly.
Implementation
Only call matching memory management functions. Do not mix and match routines. For example, when you allocate a buffer with malloc(), dispose of the original pointer with free().
Implementation
When programming in C++, consider using smart pointers provided by the boost library to help correctly and consistently manage memory.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition (opens in a new tab)
Base weaknessLikelihood of exploit: Medium
The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.
Implementation
The most basic advice for TOCTOU vulnerabilities is to not perform a check before the use. This does not resolve the underlying issue of the execution of a function on a resource whose state and identity cannot be assured, but it does help to limit the false sense of security given by the check.
Implementation
When the file being altered is owned by the current user and group, set the effective gid and uid to that of the current user and group when executing this statement.
Architecture and Design
Limit the interleaving of operations on files from multiple processes.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
OWASP ASVS 4.0.3
V1.11.3 (opens in a new tab)
V11.1.6 (opens in a new tab)
V1.11.2 (opens in a new tab)
Attack patterns
Leveraging Race Conditions via Symbolic Links (opens in a new tab)
Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 5 Nov 2026, 21:18 UTC

Public exploits and detectionGitHub proofs of concept

WeaknessesCWE-825, CWE-826, CWE-763 +1

Technical details

References

Community reviews

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