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CVE-2026-22990 Linux CVE debrief

The Linux kernel has been updated to address a HIGH-severity vulnerability, CVE-2026-22990, in the libceph component. This vulnerability, with a CVSS score of 7.5, could allow an attacker to cause a denial of service (DoS) by providing a maliciously corrupted osdmap. The issue arises from the overzealous use of BUG_ON in the osdmap_apply_incremental() function, which could trigger unexpectedly and lead to a system crash. Instead of BUGing, the function now declares the incremental osdmap as invalid. Users should update their Linux kernel to the latest version to mitigate this vulnerability.

Vendor
Linux
Product
Unknown
CVSS
HIGH 7.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-01-23
Original CVE updated
2026-06-17
Advisory published
2026-01-23
Advisory updated
2026-06-17

Who should care

System administrators and users of Linux kernel versions prior to the patched versions should be aware of this vulnerability. This includes users of Linux distributions that have not yet updated their kernels to include the fix. The vulnerability could be exploited remotely, making it essential for administrators to update their systems promptly.

Technical summary

The vulnerability is located in the libceph component of the Linux kernel, specifically in the osdmap_apply_incremental() function. The function previously used BUG_ON to handle cases where the incremental osdmap epoch did not match the expected value. However, this approach could lead to system crashes if the osdmap was maliciously corrupted. The fix replaces BUG_ON with a check that declares the incremental osdmap as invalid in such cases, preventing the system from crashing.

Defensive priority

High

Recommended defensive actions

  • Update the Linux kernel to the latest version available.
  • Review and apply patches provided by the Linux kernel maintainers.
  • Ensure that systems are configured to receive and apply kernel updates automatically.
  • Monitor system logs for any suspicious activity related to the libceph component.
  • Consider implementing additional security measures, such as network segmentation and access controls, to limit the attack surface.
  • Regularly review and update system configurations to ensure they align with security best practices.

Evidence notes

The information provided is based on the CVE-2026-22990 record and related sources from the Linux kernel community. The vulnerability has been addressed through a series of patches applied to the Linux kernel. The patches are available on the Linux kernel Git repository.

Official resources

public