PatchSiren cyber security CVE debrief
CVE-2026-23392 Linux CVE debrief
A high-severity vulnerability, CVE-2026-23392, was found in the Linux kernel. This vulnerability is caused by a use-after-free error in the netfilter subsystem, specifically in the nf_tables component. The vulnerability occurs when the flowtable is released after an RCU grace period on error, allowing a hook that already refers to this flowtable to be registered, exposing the flowtable to the packet path and nfnetlink_hook control plane. The affected Linux kernel versions are 4.16.1 to 6.1.167, 6.2 to 6.6.130, 6.7 to 6.12.78, 6.13 to 6.18.20, 6.19 to 6.19.10, and 7.0 rc1 to rc7.
- Vendor
- Linux
- Product
- Unknown
- CVSS
- HIGH 7.8
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-07-14
- Original CVE updated
- 2026-07-28
- Advisory published
- 2026-07-14
- Advisory updated
- 2026-07-28
Who should care
This vulnerability affects Linux kernel versions 4.16.1 to 6.1.167, 6.2 to 6.6.130, 6.7 to 6.12.78, 6.13 to 6.18.20, 6.19 to 6.19.10, and 7.0 rc1 to rc7. Users of these versions should take immediate action to mitigate the vulnerability. The operators, platform, vulnerability-management, and security teams should review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
Technical summary
The vulnerability is caused by a use-after-free error in the netfilter subsystem, specifically in the nf_tables component. The error occurs when the flowtable is released after an RCU grace period on error, allowing a hook that already refers to this flowtable to be registered. This can be exploited by an attacker to execute arbitrary code or cause a denial-of-service (DoS) attack. The affected Linux kernel versions are 4.16.1 to 6.1.167, 6.2 to 6.6.130, 6.7 to 6.12.78, 6.13 to 6.18.20, 6.19 to 6.19.10, and 7.0 rc1 to rc7.
Defensive priority
High
Recommended defensive actions
- Apply patches from Linux kernel maintainers
- Update Linux kernel to a version that is not vulnerable
- Implement compensating controls, such as firewall rules or intrusion detection systems
- Monitor system logs for suspicious activity
- Perform regular vulnerability scans and penetration testing
- Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
- Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
Evidence notes
The vulnerability was reported by KASAN and is described as a use-after-free error in the netfilter subsystem. The CVE record was published on 2026-03-25T11:16:39.873Z and last modified on 2026-07-14T13:18:32.290Z. The affected product deployments should be reviewed for potential exposure.
Sources and references
Verified primary and authoritative sources
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CVE-2026-23392 CVE Program record
Publisher, destination, and source semantics verified
URL: https://www.cve.org/CVERecord?id=CVE-2026-23392
CVE Program - Official CVE Program record with source-provided CVE metadata.
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CVE-2026-23392 NVD vulnerability detail
Publisher, destination, and source semantics verified
URL: https://nvd.nist.gov/vuln/detail/CVE-2026-23392
NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.
Supplemental references
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Mitigation or vendor reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/7e3955b282eae20d61c75e499c75eade51c20060
416baaa9-dc9f-4396-8d5f-8c081fb06d67 - Patch
-
Mitigation or vendor reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/adee3436ccd29f1e514c028899e400cbc6d84065
416baaa9-dc9f-4396-8d5f-8c081fb06d67 - Patch
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Mitigation or vendor reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/c8092edb9a11f20f95ccceeb9422b7dd0df337bd
416baaa9-dc9f-4396-8d5f-8c081fb06d67 - Patch
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Mitigation or vendor reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/d2632de96ccb066e0131ad1494241b9c281c60b8
416baaa9-dc9f-4396-8d5f-8c081fb06d67 - Patch
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Mitigation or vendor reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/d73f4b53aaaea4c95f245e491aa5eeb8a21874ce
416baaa9-dc9f-4396-8d5f-8c081fb06d67 - Patch
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Mitigation or vendor reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/e78a2dcc7cfb87b64a631441ca7681492b347ef6
416baaa9-dc9f-4396-8d5f-8c081fb06d67 - Patch
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Source reference
Unverified legacy reference
URL: https://cert-portal.siemens.com/productcert/html/ssa-019113.html
0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
Methodology and review provenance
AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.