How severe is CVE-2026-53303?

CVE-2026-53303 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.

Is CVE-2026-53303 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-53303?

CVE-2026-53303 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-53303?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-53303 published?

CVE-2026-53303 was published on 2026-06-26 and last updated on 2026-07-06.

CVE-2026-53303

CVE-2026-53303 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

Severity: High (CVSS 3.x base score 7.1)
EPSS exploit prediction: 0% (3rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Linux Linux Kernel
Published: 2026-06-26
Last modified: 2026-07-06

Description

In the Linux kernel, the following vulnerability has been resolved: f2fs: protect extension_list reading with sb_lock in f2fs_sbi_show() In f2fs_sbi_show(), the extension_list, extension_count and hot_ext_count are read without holding sbi->sb_lock. If a concurrent sysfs store modifies the extension list via f2fs_update_extension_list(), the show path may read inconsistent count and array contents, potentially leading to out-of-bounds access or displaying stale data. Fix this by holding sb_lock around the entire extension list read and format operation.

Frequently asked questions

What is CVE-2026-53303?: In the Linux kernel, the following vulnerability has been resolved: f2fs: protect extension_list reading with sb_lock in f2fs_sbi_show() In f2fs_sbi_show(), the extension_list, extension_count and hot_ext_count are read without holding sbi->sb_lock. If a concurrent sysfs store modifies the extension list via f2fs_update_extension_list(), the show path may read inconsistent count and array contents, potentially leading to out-of-bounds access or displaying stale data. Fix this by holding sb_lock around the entire extension list read and format operation.
How severe is CVE-2026-53303?: CVE-2026-53303 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
Is CVE-2026-53303 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-53303?: CVE-2026-53303 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-53303?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-53303 published?: CVE-2026-53303 was published on 2026-06-26 and last updated on 2026-07-06.

References

Affected products (1)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

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