CVEPublished 2026-05-26Modified 2026-05-260 articles on news5 live referencesNVD data

CVE-2026-46431

Vulnerability data via NVD (ingested)

CVSS v3.1
4.3
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
EPSS percentile
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.

Timeline
Published 2026-05-26
Modified 2026-05-26

External references

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

More intel sources (5)

Known PoCs on GitHub

No public proof-of-concept repositories found for CVE-2026-46431 on GitHub.
We haven't classified any articles referencing CVE-2026-46431 yet. The external references above still apply.