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.
References
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 - |
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
