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CVE-2026-52992 Linux CVE debrief

A vulnerability in the Linux kernel has been resolved by adding validation for nzones in adfs_validate_bblk(). This change rejects ADFS disc records with a zero zone count during boot block validation, preventing an out-of-bounds write when nzones is 0. The vulnerability could lead to an out-of-bounds write when adfs_read_map() returns ZERO_SIZE_PTR, and adfs_map_layout() writes to dm[-1]. Linux kernel users and maintainers should be aware of this vulnerability and ensure they are running a patched kernel to prevent potential out-of-bounds writes. The fix adds a check to reject ADFS disc records with nzones == 0 during boot block validation.

Vendor
Linux
Product
Unknown
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-24
Original CVE updated
2026-07-14
Advisory published
2026-06-24
Advisory updated
2026-07-14

Who should care

Linux kernel users, maintainers, and security teams should be aware of this vulnerability and ensure they are running a patched kernel to prevent potential out-of-bounds writes. This includes operators managing Linux-based systems, platform administrators, and vulnerability management teams who need to assess and mitigate this vulnerability. Affected product deployments should be confirmed in managed environments, and an owner should be assigned for follow-up.

Technical summary

The Linux kernel vulnerability CVE-2026-52992 involves a flaw in the adfs_validate_bblk() function. When nzones is 0, adfs_read_map() returns ZERO_SIZE_PTR, leading to an out-of-bounds write in adfs_map_layout(). The fix adds a check to reject ADFS disc records with nzones == 0 during boot block validation, preventing the out-of-bounds write. This vulnerability was found by syzkaller and resolved by adding a validation check for nzones in adfs_validate_bblk(). Linux kernel users and maintainers should verify their systems and apply patches to prevent potential exploitation.

Defensive priority

High priority for Linux kernel maintainers and users to apply patches and prevent potential exploitation. Systems should be reviewed for potential exposure, and compensating controls should be considered while patches are applied. Monitoring and detection capabilities should be reviewed to identify potential exploitation attempts. Asset inventory and rollback/change windows should be considered to minimize potential impact. Source tracking and exposure review should be performed to ensure that all affected systems are identified and remediated. Vendor patch guidance should be followed to ensure that patches are applied correctly. The vulnerability has been publicly disclosed, and defenders should review the official advisory or CVE record to validate affected scope, severity, and vendor guidance. Affected product deployments should be confirmed in managed environments, and an owner should be assigned for follow-up. Exceptions should be tracked, and remediated assets should be retested and closed only after evidence is documented. Relevant monitoring, detection, and logs should be reviewed for exposed assets that need extra review. Compensating controls should be reviewed for exposed systems while remediation is scheduled and verified. Systems should be checked for relevant monitoring, detection, and logs for exposed assets that need extra review. Tracking exceptions, retesting remediated assets, and closing the item only after evidence is documented is crucial. 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. Review 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. Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up. The vulnerability was found by syzkaller and resolved by adding a validation check for nzones in adfs_valid

Recommended defensive actions

  • Apply kernel patches to validate nzones in adfs_validate_bblk()
  • Ensure systems are running a patched kernel version
  • Monitor for potential exploitation attempts
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
  • Review 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
  • Review compensating controls for exposed systems while remediation is scheduled and verified

Evidence notes

The vulnerability was found by syzkaller and resolved by adding a validation check for nzones in adfs_validate_bblk(). The fix prevents an out-of-bounds write when nzones is 0. Linux kernel users and maintainers should verify their systems and apply patches to prevent potential exploitation. Evidence is limited to public sources and may not reflect the full scope or impact of the vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-52992 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-52992

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-52992 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-52992

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/1586bd2d2fb436a26df20a70e78b000d34a7d159

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/1f0ed0f57f0fc87e46fe19a05435c214dc464be2

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/33aafd2418a59c96c0389d47ea09026661fa9ec6

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/60d82592ac8b5637fbed871381eb0a16df0a492e

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/6ff8cca5cdb4f2e0ea6d28ecd78479dd3f221ebc

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/a11372a8b1ceaa5e950a84b3b5fbf8228f25e277

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/a3fd5dc1c7b0aae947a67dc2e2c037d57557a4de

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

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.