CyberSecBulletin
CVE-2026-19908NVD status: Deferred

Q80: Missing Authentication for Critical Functionality

Published Updated By the CyberSecBulletin desk

CVE-2026-19908 is a high-severity missing authentication for critical functionality vulnerability in Q80 from PAX Technology, with a CVSS 3.0 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. Affected Q80 versions: 2.6.33.6690R. The record does not name a fixed version, so check the vendor advisory. 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. Check which version of Q80 you run against the affected versions below, and install the vendor's latest release.

Affected products and versions

VendorProductAffected versionsFixed in
PAX TechnologyQ802.6.33.6690RNot stated

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.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
LowLimited modification of data is possible.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N. Scored by CNA (trendmicro.com).

Official description

PAX Technology Q80 XCB Daemon Missing Authentication Vulnerability. This vulnerability allows network-adjacent attackers to disclose sensitive information and modify configuration on affected installations of PAX Technology Q80. Authentication is not required to exploit this vulnerability. The specific flaw exists within the XCB daemon. The issue results from the lack of authentication prior to allowing access to functionality. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of root. Was ZDI-CAN-30584.

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

The underlying weakness: Missing Authentication for Critical Functionality

The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.

How developers prevent this class of flaw

  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator.
  • When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to require strong authentication for users who should be allowed to access the data.

More Missing Authentication for Critical Functionality vulnerabilities (CWE-306)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Q80

All Q80 vulnerabilities

Recent Missing Authentication for Critical Functionality vulnerabilities

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