CVE-2026-63964
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.
Affected versions
Linux kernel versions
5.2
and later are affected. Fixed in
5.10.259,
5.15.210,
6.1.176,
6.6.143,
6.12.93,
6.18.35,
7.0.12,
7.1
and their respective stable series.
References
8 totalFrequently asked questions
-
What is CVE-2026-63964?
CVE-2026-63964 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 5.2 onward and has been patched in 5.10.259, 5.15.210, 6.1.176 and others. CVE-2026-63964 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
-
Is there a patch available for CVE-2026-63964?
Yes. CVE-2026-63964 has been patched. Fixed versions include 5.10.259, 5.15.210, 6.1.176 and others. If you are running Linux kernel 5.2 or later up to the fix versions, apply the relevant patch for your kernel branch.
-
Is CVE-2026-63964 actively exploited?
No. CVE-2026-63964 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.