CVE-2026-59104
UgCS server HCI authentication bypass with empty credentials
Description
UgCS server before 6.2 contains an authentication bypass in the HCI protocol login handler (LoginHandler) exposed on TCP port 3334. When the user database contains exactly one user (the default single-operator installation), a LoginRequest with empty userLogin and userPassword fields is interpreted as \"use the only user\" rather than as invalid credentials, and the server returns a fully authenticated session. Because the service listens on all interfaces (0.0.0.0) without TLS by default, an unauthenticated remote attacker with network access to port 3334 can obtain an authenticated session without knowing any credential and then issue privileged commands, including commanding connected drones and uploading flight routes.
INFO
Published Date :
Nov. 6, 2026, 10:17 p.m.
Last Modified :
Nov. 6, 2026, 10:17 p.m.
Remotely Exploit :
Yes !
Source :
a6d3dc9e-0591-4a13-bce7-0f5b31ff6158
Affected Products
The following products are affected by CVE-2026-59104
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | a6d3dc9e-0591-4a13-bce7-0f5b31ff6158 | ||||
| CVSS 3.1 | CRITICAL | MITRE-CVE | ||||
| CVSS 4.0 | CRITICAL | a6d3dc9e-0591-4a13-bce7-0f5b31ff6158 | ||||
| CVSS 4.0 | CRITICAL | a6d3dc9e-0591-4a13-bce7-0f5b31ff6158 |
Solution
- Update UgCS server to version 6.2 or later.
- Ensure the user database has more than one user.
- Configure TLS for the HCI protocol.
- Restrict network access to port 3334.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-59104.
| URL | Resource |
|---|---|
| https://offseq.com/en/research/ugcs-cve-2026-59104/ | |
| https://www.ugcs.com/ |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-59104 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-59104
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-59104 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-59104 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by a6d3dc9e-0591-4a13-bce7-0f5b31ff6158
Nov. 06, 2026
Action Type Old Value New Value Added Description UgCS server before 6.2 contains an authentication bypass in the HCI protocol login handler (LoginHandler) exposed on TCP port 3334. When the user database contains exactly one user (the default single-operator installation), a LoginRequest with empty userLogin and userPassword fields is interpreted as \"use the only user\" rather than as invalid credentials, and the server returns a fully authenticated session. Because the service listens on all interfaces (0.0.0.0) without TLS by default, an unauthenticated remote attacker with network access to port 3334 can obtain an authenticated session without knowing any credential and then issue privileged commands, including commanding connected drones and uploading flight routes. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/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 Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-287 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/59xxx/CVE-2026-59104.json">CVE-2026-59104</a> Added Reference https://offseq.com/en/research/ugcs-cve-2026-59104/ Added Reference https://www.ugcs.com/