๐Ÿ›ก๏ธ CVE-2026-46431
๐ŸŸก CVSS 4.3 โ€” Medium โœ… No Known Exploit CWE-942 NVD
4.3
CVSS Score
0 Low4 Medium7 High9 Critical10

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.

Details

Severity Medium
CVSS Score 4.3
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
CWE CWE-942
Public Exploit โœ… No
Source NVD
Published 2026-05-20
Updated 2026-06-09
Modified 2026-06-08
Fix URL N/A

Affected Packages

Software From version Fixed in
github.com/xyproto/algernon โ€” โ€”
unknown โ€” โ€”

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