CyberSecBulletin
CVE-2026-77056NVD status: Deferred

black_debian_images: Use of Default Credentials

CVE-2026-77056 is a high-severity use of default credentials vulnerability in black_debian_images from boneIO, with a CVSS 4.0 base score of 7.1 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists version 1.6.0 as the first without the flaw, so updating black_debian_images to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.36% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update black_debian_images to 1.6.0 or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
boneIOblack_debian_images1.2.0 up to, but not including, 1.6.01.6.0

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
AdjacentThe attacker must be on the same local network segment.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Attack requirements
NoneThe attack does not depend on a particular deployment or configuration.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Confidentiality (vulnerable system)
HighSerious loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
NoneNo loss of integrity on the vulnerable system.
Availability (vulnerable system)
NoneNo loss of availability on the vulnerable system.
Confidentiality (other systems)
NoneNo loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
NoneNo loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
NoneNo loss of availability on systems beyond the vulnerable one.

Vector: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA (cert.pl).

Official description

boneIO black_debian_images ships with a Mosquitto MQTT broker that uses the same default credentials on all devices. These credentials are publicly documented on github, and there is no indication in the instructions to change them. A remote attacker can use them to gain full read and write access to the broker, allowing control of connected relays, blinds, and gates, and injection of fake entities into a linked Home Assistant installation. This issue was fixed in version 1.6.0 of the image: MQTT passwords are generated per device at first boot. Devices upgraded from earlier versions keep their existing broker credentials; from boneio 1.6.0 the web panel reports credentials that are still the published defaults, and the owner has to change them.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Use of Default Credentials

The product uses default credentials (such as passwords or cryptographic keys) for potentially critical functionality.

How developers prevent this class of flaw

  • Prohibit use of default, hard-coded, or other values that do not vary for each installation of the product - especially for separate organizations.
  • Force the administrator to change the credential upon installation.
  • The product administrator could change the defaults upon installation or during operation.

More Use of Default Credentials vulnerabilities (CWE-1392)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).

References

Other vulnerabilities in black_debian_images

All black_debian_images vulnerabilities

Recent Use of Default Credentials vulnerabilities

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