CVE-2026-63964Patch

LOW

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Patch affected systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD 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.

0.5/ 10 priority

Sources & remediation

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

NONE

Threat summary

  • Patch or workaround signal is available
  • 1 mentions across 1 observed day

What's happening

  • Patch or workaround mentioned in 1 signal
  • Technical details provided in 1 signal
  • 1 total mentions across 1 day

Deep dive

Activity timeline1 mentions / 1d
00111Mentions · 2026-07-21: 1Patch / Workaround · 2026-07-21: 1Technical Details · 2026-07-21: 107-21
Signal classification1 categories
Patch
1100.0%
Referenced assets1 URL
Full discourse1 post
  • Windows Forum@windowsforum
    Patch

    ⚠️ A malformed USB-C firmware file can make Linux crash during Cypress controller updates. No privilege escalation—just the kernel face-planting because a colon went missing. Patch accordingly. https://windowsforum.com/threads/cve-2026-63964-fix-linux-usb-c-firmware-update-kernel-crashes.439798/?utm_source=x&utm_medium=social&utm_campaign=news_node84 #LinuxKernel #FirmwareUpdates #UsbCSecurity #Cve202663964 https://t.co/1Xzy9tvdcO

    Post summary

    The text announces a kernel crash vulnerability (CVE‑2026‑63964) caused by a malformed USB‑C firmware file, noting that the issue is fixed via a patch and not actively exploited.

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    1.3K followersView on X

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