CVE Catalog

CVE-2026-63964

Low risk· EPSS 11%
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.21%

11th percentile - higher than 11% of all known CVEs

Summary

In the Linux kernel's USB Type-C UCSI CCG driver, a vulnerability exists due to missing validation of firmware image headers. If the firmware image lacks a ':' character, strnchr() returns NULL, leading to a NULL pointer dereference and system crash (oops).

Risk Assessment

A root attacker can place a crafted file in /lib/firmware and trigger the do_flash sysfs attribute, causing a kernel panic and potential denial of service.

Recommendation

Immediately update the Linux kernel to a version containing the fix that rejects firmware images without a ':' header (returning -EINVAL).

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: usb: typec: ucsi: ccg: reject firmware images without a ':' record header do_flash() locates the first .cyacd record with p = strnchr(fw->data, fw->size, ':'); while (p < eof) { s = strnchr(p + 1, eof - p - 1, ':'); ... } If the firmware image contains no ':' byte, strnchr() returns NULL. NULL compares less than the valid kernel pointer eof, so the loop body runs and strnchr() is called with p + 1 == (void *)1 and a length of roughly (unsigned long)eof, causing a wonderful crash. The not_signed_fw fallthrough earlier in do_flash() and the chip-state branches in ccg_fw_update_needed() allow an unsigned blob to reach this loop, so a root user who can place a crafted file under /lib/firmware and write the do_flash sysfs attribute can trigger the oops. Bail out with -EINVAL when the initial strnchr() returns NULL.

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