CVE-2026-31532

Description

In the Linux kernel, the following vulnerability has been resolved: can: raw: fix ro->uniq use-after-free in raw_rcv() raw_release() unregisters raw CAN receive filters via can_rx_unregister(), but receiver deletion is deferred with call_rcu(). This leaves a window where raw_rcv() may still be running in an RCU read-side critical section after raw_release() frees ro->uniq, leading to a use-after-free of the percpu uniq storage. Move free_percpu(ro->uniq) out of raw_release() and into a raw-specific socket destructor. can_rx_unregister() takes an extra reference to the socket and only drops it from the RCU callback, so freeing uniq from sk_destruct ensures the percpu area is not released until the relevant callbacks have drained. [mkl: applied manually]

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CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0001

Probability of exploitation

0.02%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-416 Use After Free

Affected Products

Vendor	Product	Versions
linux	linux_kernel	4.1 — 6.6.136
linux	linux_kernel	6.7 — 6.12.83
linux	linux_kernel	6.18 — 6.18.24
linux	linux_kernel	6.19 — 6.19.14
linux	linux_kernel	7.0 — 7.0.1

References

Advisories & Patches

https://git.kernel.org/stable/c/1a0f2de81f7fbdc538fc72d7d74609b79bc83cc0 https://git.kernel.org/stable/c/34c1741254ff972e8375faf176678a248826fe3a https://git.kernel.org/stable/c/572f0bf536ebc14f6e7da3d21a85cf076de8358e https://git.kernel.org/stable/c/5e9cfffad898bbeaafd0ea608a6d267362f050fc https://git.kernel.org/stable/c/7201a531b9a5ed892bfda5ded9194ef622de8ffa https://git.kernel.org/stable/c/a535a9217ca3f2fccedaafb2fddb4c48f27d36dc

Frequently Asked Questions

What is CVE-2026-31532? +

In the Linux kernel, the following vulnerability has been resolved: can: raw: fix ro->uniq use-after-free in raw_rcv() raw_release() unregisters raw CAN receive filters via can_rx_unregister(), but receiver deletion is deferred with call_rcu(). This leaves a window where raw_rcv() may still be running in an RCU read-side critical section after raw_release() frees ro->uniq, leading to a use-after-free of the percpu uniq storage. Move free_percpu(ro->uniq) out of raw_release() and into a raw-specific socket destructor. can_rx_unregister() takes an extra reference to the socket and only drops it from the RCU callback, so freeing uniq from sk_destruct ensures the percpu area is not released until the relevant callbacks have drained. [mkl: applied manually] It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2026-31532? +

CVE-2026-31532 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0001, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-31532? +

CVE-2026-31532 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-31532? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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