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CVE-2026-53259 Linux CVE debrief

CVE-2026-53259 is a HIGH severity vulnerability in the Linux kernel, with a CVSS score of 7.8. The vulnerability is related to the handling of anycast addresses in the IPv6 stack. A use-after-free bug can occur when a device is torn down while an anycast address is being added to the global hash. This can lead to a situation where a freed memory location is accessed, causing a crash or potentially allowing an attacker to execute arbitrary code. The vulnerability was introduced due to a race condition between the addition of an anycast address to the global hash and the teardown of a device. To fix this issue, the kernel developers moved the addition of the anycast address to the global hash inside the idev->lock section, ensuring that the ac_list and hash insertions are atomic with respect to teardown.

Vendor
Linux
Product
Unknown
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-25
Original CVE updated
2026-06-28
Advisory published
2026-06-25
Advisory updated
2026-06-28

Who should care

Linux kernel developers, maintainers, and users of Linux-based systems should care about this vulnerability. The vulnerability can be exploited by an attacker with local access to the system, potentially allowing them to crash the system or execute arbitrary code. Linux distributions and vendors should apply the patch to affected versions of the Linux kernel.

Technical summary

The vulnerability is caused by a use-after-free bug in the IPv6 anycast address handling code. When a device is torn down, the anycast address is removed from the global hash, but it may still be referenced by other parts of the code. To fix this issue, the kernel developers moved the addition of the anycast address to the global hash inside the idev->lock section, ensuring that the ac_list and hash insertions are atomic with respect to teardown. This change prevents the use-after-free bug and fixes the vulnerability.

Defensive priority

Apply the patch to affected versions of the Linux kernel. Review and update Linux kernel configurations to ensure that the fix is applied.

Recommended defensive actions

  • Apply the patch to affected versions of the Linux kernel
  • Review and update Linux kernel configurations to ensure that the fix is applied
  • Monitor Linux kernel updates and patches for future vulnerabilities
  • Consider implementing additional security measures, such as address space layout randomization (ASLR) and data execution prevention (DEP)
  • Perform regular vulnerability scans and penetration testing to identify potential issues

Evidence notes

The vulnerability was reported by syzbot and fixed by the Linux kernel developers. The fix was backported to stable kernel versions. The CVE record and NVD details provide additional information on the vulnerability.

Official resources

This article is AI-assisted and based on the supplied source corpus.