Cyber Posture

CVE-2026-45728

High

Published: 26 May 2026

Published
26 May 2026
Modified
26 May 2026
KEV Added
Patch
CVSS Score 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS Score 0.0003 9.6th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-45728 is a high-severity Generation of Error Message Containing Sensitive Information (CWE-209) vulnerability. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 9.6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190).
Threat & Defense Details

Likely Mitigating ControlsAI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-209

Detects error messages that leak sensitive information as evidence of disclosure.

addresses: CWE-1188

Requires documented secure initialization practices and avoidance of insecure defaults in configuration baselines.

addresses: CWE-1188

Reviewing and updating baseline when components are installed or upgraded prevents initialization with insecure defaults.

addresses: CWE-1188

Requiring explicit configuration to minimal functionality overrides insecure defaults that would otherwise enable excess capabilities.

addresses: CWE-209

The control directly mitigates generation of error messages containing sensitive authentication details by requiring obscured feedback instead of verbose responses.

addresses: CWE-540

Detection and removal of spilled information addresses cases where sensitive data was included in source code.

addresses: CWE-1188

Tailoring replaces or augments insecure default initializations with system-specific values and compensating controls before deployment.

addresses: CWE-1188

Central configuration overrides or replaces insecure default initializations that would otherwise be left unchanged on each system.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

Vulnerability in public-facing web server enables remote source code disclosure via triggered errors in debug mode.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v18.1

NVD Description

Algernon is a small self-contained pure-Go web server. Prior to 1.17.7, when Algernon is invoked with a single file path instead of a directory, singleFileMode is set to true and debugMode is forcibly enabled. debugMode activates the PrettyError renderer, which…

more

on any Lua or template error response dumps the absolute path of the file that errored, complete byte contents of that file, and exception or parser error text. This response is served with HTTP 200 OK to whoever sent the request that triggered the error. Any client able to reach the server and able to provoke a runtime error in the served script obtains the full server-side source of that script and of any sibling Lua data file consulted during the request. This vulnerability is fixed in 1.17.7.

Deeper analysisAI

Automated synthesis unavailable for this CVE.

Details

CWE(s)
OWASP Top 10 Web 2025

EU & UK References

References