CVE-2026-63964

MEDIUM
MEDIUM Priority: 0.01 BB Relevance: 36/100
Published: 2026-07-19 Modified: 2026-10-30 First seen: 2026-10-30 Status: active

Attack Surface

Low Complexity No Interaction

CVSS Vector Breakdown

AV: Local
AC: Low
PR: Low
UI: None
S: Unchanged
C: None
I: None
A: High

Description

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.

Weakness Classification (1)

Affected Software (6)

VendorProductVersion
linux linux_kernel 5.2 – 5.10.259
linux linux_kernel 7.1
linux linux_kernel 7.1
linux linux_kernel 7.1
linux linux_kernel 7.1
linux linux_kernel 7.1

Bug Bounty Relevance

36 / 100
✓ Low complexity
✓ No user interaction

CVSS Score

5.5 / 10.0 v3.1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploitation Probability

0.16%
Raw Score 0.001560
Percentile 4.7%
Date 2026-10-31

EPSS Trend

2026-10-31
0.00156
2026-10-30
0.00211

Intelligence Sources

nvd ref →