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CVE-2026-99007 Linux CVE debrief

A Linux kernel vulnerability has been identified in the drm/fb-helper module. The issue arises when fbdev_probe() fails, and the setup is not properly deferred, leading to potential use of stale mode sets. This can cause a WARN_ON() in __drm_atomic_helper_set_config() when a later .restore() call is made. The vulnerability affects Linux kernel versions and could lead to system instability if not patched. Defenders should verify Linux kernel versions, apply patches, and monitor for potential issues. The CVE record and source item provide details on the vulnerability, including its description and affected versions.

Vendor
Linux
Product
Unknown
CVSS
Unknown
CISA KEV
Not listed in stored evidence
Original CVE published
2026-10-23
Original CVE updated
2026-10-30
Advisory published
2026-10-23
Advisory updated
2026-10-30

Who should care

Linux kernel developers and maintainers, as well as users of Linux-based systems, should assess their exposure to this vulnerability and apply patches as necessary. System administrators should monitor for .restore() calls that may trigger the WARN_ON() issue. Linux kernel developers should review and apply patches to ensure the drm/fb-helper module is updated. Additionally, defenders should verify Linux kernel versions and apply patches to prevent .

Why it matters

This vulnerability in the Linux kernel's drm/fb-helper module can cause a WARN_ON() issue when a later .restore() call is made. Defenders should verify Linux kernel versions, apply patches, and monitor for potential issues.

  • Defenders should verify Linux kernel versions and apply patches to prevent potential WARN_ON() issues.
  • System administrators should monitor for .restore() calls that may trigger the WARN_ON() issue.
  • Linux kernel developers should review and apply patches to ensure the drm/fb-helper module is updated.

Technical summary

The drm/fb-helper module in the Linux kernel does not properly defer setup when fbdev_probe() fails. This can lead to stale mode sets being used, causing a WARN_ON() in __drm_atomic_helper_set_config() during a later .restore() call. The vulnerability affects Linux kernel versions and could lead to system instability if not patched. The issue arises from the failure of fbdev_probe(), which causes the setup to not be properly deferred. This results in the use of stale mode sets, leading to a WARN_ON() issue. The CVE record and source item provide details on the vulnerability, including its description and affected versions.

Defensive priority

Medium

Recommended defensive actions

  • Review and apply the provided patches to ensure the drm/fb-helper module is updated.
  • Verify the Linux kernel version and update to a patched version if necessary.
  • Monitor for potential .restore() calls that may trigger the WARN_ON() issue.
  • Perform a thorough review of system configurations to identify potential exposure.
  • Implement compensating controls for exposed systems while remediation is scheduled and verified.
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented.
  • Review relevant monitoring, detection, and logs for exposed assets that need extra review.

Evidence notes

The CVE record and source item provide details on the vulnerability, including its description and affected versions. However, the corpus does not establish specific exploitation or impact, and remediation priority is not explicitly stated.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-99007 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-99007

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

  • CVE-2026-99007 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-99007

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

Supplemental references

  • drm/fb-helper: defer setup when fbdev_probe() fails, not just on -EAGAIN

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/99xxx/CVE-2026-99007.json

    cve_program_cvelist_v5

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/423c871a586cff8b29f48db00e3c45c21d0e8121

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/e5f8f6e0f0a18c77c04b757d72319d897a0b4bc1

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/9124411cb91b129ff3ffb0d723ecba7a5bf893f9

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/4a2006c675758f0c765b36fec6b49d17e89159cf

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/3b303696f61461b3569019d7fcac6a646652b2b4

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/4e7b508c7c60dec7a86b7eb2a1b7e6d174afa457

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/d510ed273854177f0a3ed330145858b2fe667f81

    Supplemental source

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.