CVE-2026-63964

usb: typec: ucsi: ccg: reject firmware images without a ':' record header

MEDIUM
5.5
CVSS Score
Published: July 19, 2026 at 02:55 PM UTC
Updated: October 30, 2026 at 05:29 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.2%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

5.11 ≤ v < 5.15.2105.16 ≤ v < 6.1.1765.2 ≤ v < 5.10.2596.13 ≤ v < 6.18.356.19 ≤ v < 7.0.126.2 ≤ v < 6.6.1436.7 ≤ v < 6.12.935.25c9ae5a87573d38cfc4c740aafda2fa6ce06e4017.1
Vendor states this is fixed in 2f395ca1263bd181995eb829f5943a83a20db213 (fixed)
Vendor states this is fixed in 3f432b8203066c26770fe6ea591361f10021dd6b (fixed)
Vendor states this is fixed in 6526f8684f72391138353642af908803ba70795e (fixed)
Vendor states this is fixed in a38ed87818b2419090fb1a6338ddce6842b65dfa (fixed)
Vendor states this is fixed in b41dfc033fe594e152648050e95b9489cd53e9e3 (fixed)
Vendor states this is fixed in c4ee519b06389e59ba2d6aa722fcc4a02a8bbcbb (fixed)
Vendor states this is fixed in c8460de584fe5415d212cfdd127d4db90835a450 (fixed)
Vendor states this is fixed in d7486952bf74e546ee3748fb14b2d07881fa6273 (fixed)
Vendor states this is fixed in 5.10.259 (unaffected)
Vendor states this is fixed in 5.15.210 (unaffected)
Vendor states this is fixed in 5.2 (unaffected)
Vendor states this is fixed in 6.1.176 (unaffected)
Vendor states this is fixed in 6.12.93 (unaffected)
Vendor states this is fixed in 6.18.35 (unaffected)
Vendor states this is fixed in 6.6.143 (unaffected)
Vendor states this is fixed in 7.0.12 (unaffected)
Vendor states this is fixed in 7.1 (unaffected)

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-476

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