CVEvulnerability

CVE-2026-46431

4.3 MEDIUM Published 2026-05-26 Modified 2026-07-24 Official page ↗
Status
Deferred
Published
2026-05-26
Last modified
2026-07-24
Assigner
[email protected]
CVSS 3.1 ([email protected])
4.3 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
Weaknesses
CWE-942

Description

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.

Related

Weakness · CWE (1)

  • CWE-942 Permissive Cross-domain Security Policy with Untrusted Domains weakness

References