PatchSiren cyber security CVE debrief
CVE-2026-23011 Linux CVE debrief
A vulnerability has been resolved in the Linux kernel, specifically in the ipv4: ip_gre module. The issue arises from the ability of team or bonding drivers to dynamically change their dev->needed_headroom and/or dev->hard_header_len, which can lead to a crash in the ipgre_header() function. This vulnerability affects users of the Linux kernel, particularly those using versions 3.10.1 to 6.19. The vulnerability was discovered through syzbot testing, which found multiple ways to crash the kernel in ipgre_header().
- Vendor
- Linux
- Product
- Unknown
- CVSS
- MEDIUM 6.6
- 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
Users of the Linux kernel, particularly those using versions 3.10.1 to 6.19, should be aware of this vulnerability and take steps to mitigate it. This includes reviewing the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance. Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.
Technical summary
The vulnerability is caused by the dynamic change of dev->needed_headroom and/or dev->hard_header_len by team or bonding drivers, which can lead to a crash in the ipgre_header() function. The issue has been resolved through a series of patches. Affected product deployments exist in managed environments and require an owner for follow-up. Review compensating controls for exposed systems while remediation is scheduled and verified.
Defensive priority
Medium
Recommended defensive actions
- Apply patches from the Linux kernel repository
- Update to the latest Linux kernel version
- Monitor for changes in dev->needed_headroom and/or dev->hard_header_len
- Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
- Review compensating controls for exposed systems while remediation is scheduled and verified
- Check relevant monitoring, detection, and logs for exposed assets that need extra review
- Track exceptions, retest remediated assets, and close the item only after evidence is documented
Evidence notes
The vulnerability was discovered through syzbot testing, which found multiple ways to crash the kernel in ipgre_header(). The issue has been resolved through a series of patches. This vulnerability affects users of the Linux kernel, particularly those using versions 3.10.1 to 6.19. The dynamic change of dev->needed_headroom and/or dev->hard_header_len by team or bonding drivers can lead to a crash in the ipgre_header() function. To verify, defenders should review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
Sources and references
Verified primary and authoritative sources
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CVE-2026-23011 CVE Program record
Publisher, destination, and source semantics verified
URL: https://www.cve.org/CVERecord?id=CVE-2026-23011
CVE Program - Official CVE Program record with source-provided CVE metadata.
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CVE-2026-23011 NVD vulnerability detail
Publisher, destination, and source semantics verified
URL: https://nvd.nist.gov/vuln/detail/CVE-2026-23011
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/06fe0801396a36cab865b34f666de1d65bc5ce8e
416baaa9-dc9f-4396-8d5f-8c081fb06d67 - Patch
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Mitigation or vendor reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/2ecf0aa7cc262472a9599cc51ba02ada0897a17a
416baaa9-dc9f-4396-8d5f-8c081fb06d67 - Patch
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Mitigation or vendor reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/554201ed0a8f4d32e719f42caeaeb2735a9ed6ca
416baaa9-dc9f-4396-8d5f-8c081fb06d67 - Patch
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Mitigation or vendor reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/8d5b6b2d79c1c22a5b0db1187a6439dff375a022
416baaa9-dc9f-4396-8d5f-8c081fb06d67 - Patch
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Mitigation or vendor reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/aa57bfea4674e6da8104fa3a37760a6f5f255dad
416baaa9-dc9f-4396-8d5f-8c081fb06d67 - Patch
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Mitigation or vendor reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/e67c577d89894811ce4dcd1a9ed29d8b63476667
416baaa9-dc9f-4396-8d5f-8c081fb06d67 - Patch
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Mitigation or vendor reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/eeb9a521de40c6fadccc12fa5205e5a1b364d5a8
416baaa9-dc9f-4396-8d5f-8c081fb06d67 - Patch
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.