CVE-2026-46431

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.
Configurations

No configuration.

History

26 May 2026, 18:16

Type Values Removed Values Added
References () https://github.com/xyproto/algernon/security/advisories/GHSA-hw27-4v2q-5qff - () https://github.com/xyproto/algernon/security/advisories/GHSA-hw27-4v2q-5qff -

26 May 2026, 17:16

Type Values Removed Values Added
New CVE

Information

Published : 2026-05-26 17:16

Updated : 2026-05-26 19:26


NVD link : CVE-2026-46431

Mitre link : CVE-2026-46431

CVE.ORG link : CVE-2026-46431


JSON object : View

Products Affected

No product.

CWE
CWE-942

Permissive Cross-domain Policy with Untrusted Domains