CVE-2026-85068
NUT blazer_usb ippon_command stack info-leak via unzeroed char tmp[64] in OUT-direction usb_control_msg
What happened?
Network UPS Tools is a collection of programs which provide a common interface for monitoring and administering UPS, PDU and SCD hardware. From 2.4.2 through 2.8.5, ippon_command in drivers/blazer_usb.c partially initializes char tmp[64] with a short Megatec status query and then passes a fixed eight-byte chunk to usb_control_msg. A malicious firmware-controlled USB device presenting the Mustek Powermust VID 0x06da and Mustek Powermust PID 0x0003 matches blazer_usb_id, selects ippon_subdriver, and can receive the uninitialized trailing stack bytes during normal polling. The disclosure is bounded and read-only, requires physical or supply-chain access to the USB bus, and has no established integrity or availability impact. This issue is scheduled to be fixed in version 2.8.6.
Affected software and versions
| Software | Version information | Fixed version |
|---|---|---|
| nutnetworkupstools | affected: >= 2.4.2, <= 2.8.5 | See vendor advisory |
Version information comes from the source record and can include unaffected products and exceptions. Distribution packages may contain backported fixes: an older upstream version alone does not prove a server is affected.
Is it being exploited?
This CVE was not listed in the CISA catalogue at our last retrieval. This does not establish that exploitation is absent.
How to respond
- Confirm the product, installed package version, and any configuration requirements in the vendor advisory.
- Follow the vendor’s remediation or workaround guidance in the references below. Structured fixed-version data is unavailable here; the publisher’s description may include a fix or workaround.
- Restart affected services if required, then verify the running version. Known exploitation may warrant investigation as well as patching.