PatchSiren cyber security CVE debrief
CVE-2026-64217 Linux CVE debrief
A HIGH severity vulnerability was found in the Linux kernel, with a CVSS score of 7.8. The vulnerability is related to the netfs: Fix overrun check in netfs_extract_user_iter() function. This issue can lead to memory corruption if iov_iter_extract_pages() overfills pages[], potentially allowing for arbitrary code execution. Linux kernel users and administrators should be aware of this vulnerability and take necessary actions to mitigate it.
- Vendor
- Linux
- Product
- Unknown
- CVSS
- HIGH 7.8
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-07-24
- Original CVE updated
- 2026-07-27
- Advisory published
- 2026-07-24
- Advisory updated
- 2026-07-27
Who should care
Linux kernel users and administrators should be aware of this vulnerability and take necessary actions to mitigate it. This includes reviewing and updating Linux kernel configurations, monitoring system logs for potential exploitation attempts, and applying patches to fix the vulnerability.
Technical summary
The vulnerability is caused by an overrun check in the netfs_extract_user_iter() function. If iov_iter_extract_pages() overfills pages[], then those pages don't get included in the iterator constructed at the end of the function. This can lead to memory corruption and potentially allow for arbitrary code execution. The issue has been resolved in the Linux kernel. Linux kernel users and administrators should review and apply patches to fix the vulnerability, monitor system logs for potential exploitation attempts, and perform compensating controls for exposed systems. Evidence limits suggest defensive verification tasks are needed to confirm exposure, including reviewing system logs and monitoring for suspicious activity.
Defensive priority
High priority should be given to patching this vulnerability as it can lead to memory corruption and potentially allow for arbitrary code execution.
Recommended defensive actions
- Apply the patch to fix the vulnerability
- Review and update Linux kernel configurations
- Monitor system logs for potential exploitation attempts
- Perform compensating controls for exposed systems
- Conduct exposure review for affected assets
- Track exceptions and retest remediated assets
Evidence notes
The CVE record was published on 2026-07-24T16:16:49.417Z and was last modified on 2026-07-27T05:16:35.803Z. The NVD entry is currently 7.8 HIGH. This vulnerability affects Linux kernel users and administrators. Evidence limits suggest defensive verification tasks are needed to confirm exposure. No additional facts are known beyond CVE and NVD details.
Official resources
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CVE-2026-64217 CVE record
CVE.org
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CVE-2026-64217 NVD detail
NVD
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Source item URL
nvd_modified
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Source reference
416baaa9-dc9f-4396-8d5f-8c081fb06d67
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Source reference
416baaa9-dc9f-4396-8d5f-8c081fb06d67
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Source reference
416baaa9-dc9f-4396-8d5f-8c081fb06d67
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Source reference
416baaa9-dc9f-4396-8d5f-8c081fb06d67
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Source reference
416baaa9-dc9f-4396-8d5f-8c081fb06d67
AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-24T16:16:49.417Z and has not been modified since then. The NVD entry is currently 7.8 HIGH.