CVE Catalog

CVE-2026-64027

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.13%

3th percentile - higher than 3% of all known CVEs

Summary

A vulnerability in the Linux kernel's network shaping mechanism (net: shaper) arises from non-atomic storage of the VALID flag relative to the XArray entry, causing a data race. This can lead to a use-after-free (UAF) during rollback operations.

Risk Assessment

The organization faces potential kernel memory corruption, which could result in system crashes or privilege escalation by a local attacker.

Recommendation

Immediately update the Linux kernel to a version containing the fix that eliminates the data race by using an explicit valid field with memory barriers.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: net: shaper: rework the VALID marking (again) Recent commit changed the semantics from NOT_VALID to VALID. I didn't realize that the flags are not stored atomically with the entry in XArray. There's still a race of reader observing a VALID mark for a slot, getting interrupted, writer replacing the entry with a different one, reader continuing, fetching the entry which is now a different pointer than the pointer for which VALID was meant. The biggest consequence of this is that we may see a UAF since net_shaper_rollback() assumed that entries without VALID can be freed without observing RCU. Looks like the XArray marks are buying us nothing at this point. Let's convert the code to an explicit valid field. The smp_load_acquire() / smp_store_release() barriers are marginally cleaner.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS