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CVE-2026-53076 Linux CVE debrief

CVE-2026-53076 is a high-severity vulnerability in the Linux kernel, with a CVSS score of 7.1. The vulnerability occurs when copying elements from a BPF_MAP_TYPE_CGROUP_STORAGE map to another pcpu map with the same value_size that is not rounded up to 8 bytes. This can happen when a CGROUP_STORAGE map is created with a value_size not aligned to 8 bytes, and a pcpu map is created with the same value_size. The issue arises because pcpu_init_value assumes all sources are rounded up to 8 bytes, but this assumption does not hold for some cases, such as CGROUP_STORAGE or skb->data. As a result, an out-of-bounds read can occur when the source has only 4 bytes while the copy size is rounded up to 8 bytes.

Vendor
Linux
Product
Unknown
CVSS
HIGH 7.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-24
Original CVE updated
2026-07-21
Advisory published
2026-06-24
Advisory updated
2026-07-21

Who should care

Linux kernel developers, administrators, and users of Linux-based systems should be aware of this vulnerability. The vulnerability can be exploited by an attacker with local access to the system, potentially leading to information disclosure.

Technical summary

The vulnerability is caused by an incorrect assumption in pcpu_init_value about the alignment of value_size in BPF maps. Specifically, when a CGROUP_STORAGE map with a non-8-byte aligned value_size is created and updated into a pcpu map with the same value_size, an out-of-bounds read can occur. This is because the verifier checks the size claimed by the source, not the size rounded up to 8 bytes by the kernel. The vulnerability can be mitigated by ensuring that value_sizes are properly aligned to 8 bytes or by applying the provided patches.

Defensive priority

High priority should be given to patching or mitigating this vulnerability, as it can be exploited by an attacker with local access to the system. Linux kernel developers and administrators should review the provided patches and apply them as soon as possible.

Recommended defensive actions

  • Apply the provided patches to the Linux kernel to fix the vulnerability.
  • Review and update Linux kernel configurations to ensure value_sizes are properly aligned to 8 bytes.
  • Monitor systems for potential exploitation attempts.
  • Consider implementing additional security controls, such as restricting access to sensitive data and limiting local access to the system.
  • Keep Linux kernel and related software up-to-date with the latest security patches.

Evidence notes

The vulnerability was reported and patched by the Linux kernel community. The CVE record and NVD details provide additional information about the vulnerability. The source item URL provides access to the NVD JSON data for this CVE.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-53076 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-53076

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

  • CVE-2026-53076 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-53076

    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/576afddfee8d1108ee299bf10f581593540d1a36

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

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/6086079e6d1c32ba4c4b422612b8aebb1129a96c

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

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/634a793d0e1c822412095d25a1338f8831ad894c

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

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/e0378419b0e20178b5d100b27c9cc7e51064202e

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

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/e19c5ed9f1922a6854073f8651a63fa7be26e9e9

    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.