Red Hat Security Advisory: kernel security update
The kernel packages contain the Linux kernel, the core of any Linux operating system. Security Fix(es): * kernel: ndisc: use RCU protection in ndisc_alloc_skb() (CVE-2025-21764) 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.
AI Analysis
Technical Summary
CVE-2025-21764 is a vulnerability in the kernel-rt packages of Red Hat Enterprise Linux 9.2, involving the use of RCU (Read-Copy-Update) protection in the ndisc_alloc_skb() function. The issue was fixed by adding RCU protection to prevent potential use-after-free conditions (CWE-416). Red Hat has released a security update (RHSA-2025:9492) that addresses this vulnerability. The update applies to Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions and Extended Life Cycle versions. The update must be installed and the system rebooted to apply the fix.
Potential Impact
The vulnerability could lead to use-after-free conditions in the kernel-rt networking code, potentially causing system instability or other unintended behavior. Red Hat rates the impact as moderate. No known exploits are reported in the wild at this time.
Mitigation Recommendations
A security update is available from Red Hat (RHSA-2025:9492) that fixes this vulnerability. Users of affected Red Hat Enterprise Linux 9.2 kernel-rt packages should apply the update promptly and reboot their systems to ensure the fix is applied. Refer to Red Hat's official update instructions at https://access.redhat.com/articles/11258 for detailed guidance.
Red Hat Security Advisory: kernel security update
Description
The kernel packages contain the Linux kernel, the core of any Linux operating system. Security Fix(es): * kernel: ndisc: use RCU protection in ndisc_alloc_skb() (CVE-2025-21764) 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.
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2025-21764 is a vulnerability in the kernel-rt packages of Red Hat Enterprise Linux 9.2, involving the use of RCU (Read-Copy-Update) protection in the ndisc_alloc_skb() function. The issue was fixed by adding RCU protection to prevent potential use-after-free conditions (CWE-416). Red Hat has released a security update (RHSA-2025:9492) that addresses this vulnerability. The update applies to Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions and Extended Life Cycle versions. The update must be installed and the system rebooted to apply the fix.
Potential Impact
The vulnerability could lead to use-after-free conditions in the kernel-rt networking code, potentially causing system instability or other unintended behavior. Red Hat rates the impact as moderate. No known exploits are reported in the wild at this time.
Mitigation Recommendations
A security update is available from Red Hat (RHSA-2025:9492) that fixes this vulnerability. Users of affected Red Hat Enterprise Linux 9.2 kernel-rt packages should apply the update promptly and reboot their systems to ensure the fix is applied. Refer to Red Hat's official update instructions at https://access.redhat.com/articles/11258 for detailed guidance.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2025:9492
- Cve Count
- 1
- Additional Cves
- []
- Cvss Version
- null
Threat ID: 6a3da1cd4853345fc18234b9
Added to database: 06/25/2026, 21:46:53 UTC
Last enriched: 06/25/2026, 22:05:32 UTC
Last updated: 07/09/2026, 07:54:19 UTC
Views: 3
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