CVE-2025-39766VulnerabilityPublished 20 Apr 2026Updated 30 Oct 2026

Red Hat Security Advisory: kernel security update

Affects Linux kernelSource GCVE Database

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Mentioned vulnerabilities

CVE-2025-68741

Not known to be exploited.

Data as of 30 Oct 2026, 06:59 UTC

Severity

High

Rated by Threat Radar · No CVSS score from NVD or the CNA

EPSS: 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation evidence

Disclosed: evidence found.
CVE published 20 Apr 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 29 Oct 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

Affected software

Product	Affected	Fixed in
Red Hat Product Security Red Hat	Affected Red Hat Red Hat Enterprise Linux Red Hat Enterprise Linux AppStream (v. 9) Red Hat Enterprise Linux BaseOS (v. 9) Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) SUSE noarch kernel-abi-stablelists-5.14.0-611.49.1.el9_7.noarch kernel-doc-5.14.0-611.49.1.el9_7.noarch x86_64	Fixed in–

AI-suggested

Red Hat has released updated kernel packages that address these vulnerabilities. Users should apply the security update as described in the Red Hat advisory (RHSA-2026:8921) and reboot affected systems to ensure the fixes take effect. No additional mitigation steps are indicated beyond applying the official update and rebooting.

Description

The kernel packages contain the Linux kernel, the core of any Linux operating system. Security Fix(es): * kernel: net/sched: Make cake_enqueue return NET_XMIT_CN when past buffer_limit (CVE-2025-39766) * kernel: scsi: qla2xxx: Fix improper freeing of purex item (CVE-2025-68741) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Impact

The vulnerabilities affect the Linux kernel core components, potentially impacting system stability and security related to network packet scheduling and SCSI device handling. The advisory rates the security impact as Important (high severity). No known exploits in the wild have been reported. The issues could lead to improper resource handling or denial of service conditions if exploited.

Summary

The Red Hat kernel security update fixes two vulnerabilities in the Linux kernel for Red Hat Enterprise Linux 9. CVE-2025-39766 addresses an issue in the net/sched subsystem where cake_enqueue did not return NET_XMIT_CN when past the buffer limit, potentially causing improper network packet handling. CVE-2025-68741 fixes improper freeing of a purex item in the scsi qla2xxx driver, which could lead to memory management issues. These fixes are included in updated kernel packages that must be installed and followed by a system reboot to take effect.

CWE-390Detection of Error Condition Without Action (opens in a new tab)
Base weaknessLikelihood of exploit: MediumOWASP Top 10 A10:2025: Mishandling of Exceptional Conditions (opens in a new tab)
The product detects a specific error, but takes no actions to handle the error.
Implementation
Properly handle each exception. This is the recommended solution. Ensure that all exceptions are handled in such a way that you can be sure of the state of your system at any given moment.
Implementation
If a function returns an error, it is important to either fix the problem and try again, alert the user that an error has happened and let the program continue, or alert the user and close and cleanup the program.
Testing
Subject the product to extensive testing to discover some of the possible instances of where/how errors or return values are not handled. Consider testing techniques such as ad hoc, equivalence partitioning, robustness and fault tolerance, mutation, and fuzzing.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
Logging (opens in a new tab)
Error Handling (opens in a new tab)
OWASP ASVS 4.0.3
V11.1.8 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
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).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 25 Jun 2026, 23:04 UTC

WeaknessesCWE-390, CWE-763

Technical details

References

Community reviews

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