CVE-2026-46431

Published: Mag 26, 2026 Last Modified: Mag 26, 2026

ExploitDB:

Other exploit source:

Google Dorks:

MEDIUM 4,3

Source: [email protected]

Attack Vector: network

Attack Complexity: low

Privileges Required: none

User Interaction: required

Scope: unchanged

Confidentiality: low

Integrity: none

Availability: none

Description

AI Translation Available

Algernon is a small self-contained pure-Go web server. Prior to 1.17.7, the SSE event server's Access-Control-Allow-Origin response header was hardcoded to the wildcard * regardless of the caller's Origin. Because EventSource does not preflight and does not send cookies, the wildcard is sufficient to let any third-party page the developer visits open a cross-origin EventSource to the SSE port and read the live filename stream from JavaScript. This vulnerability is fixed in 1.17.7.

942

Permissive Cross-domain Security Policy with Untrusted Domains

Incomplete

Abstraction: Variant Structure: Simple

Common Consequences

Security Scopes Affected:

Confidentiality Integrity Availability Access Control

Potential Impacts:

Execute Unauthorized Code Or Commands Bypass Protection Mechanism Read Application Data Varies By Context

Applicable Platforms

Technologies: Web Based, Web Server

View CWE Details

https://github.com/xyproto/algernon/security/advisories/GHS…

https://github.com/xyproto/algernon/security/advisories/GHSA-hw27-4v2q-5qff