CVE-2026-49860

EUVD-2026-38542

23.06.2026, 18:18

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.8.1, when a WebSocket connection was opened, Deno checked the destination hostname against --deny-net rules but did not re-check the IP addresses that hostname resolved to. An attacker-controlled script could use a specially crafted domain name that passes the hostname check yet resolves to a denied IP, bypassing the network restriction entirely. This vulnerability is fixed in 2.8.1.

SSRF

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	Primary	5.2 MEDIUM	LOCAL	LOW	LOW	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

Base Score

CVSS 3.x

EPSS Score

Percentile: 1.03%

Affected Products (NVD)

Vendor	Product	Version
deno	deno	𝑥 < 2.8.1

𝑥

= Vulnerable software versions

Common Weakness Enumeration

CWE-918 - Server-Side Request Forgery (SSRF)
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.

References

https://github.com/denoland/deno/security/advisories/GHSA-83pc-3rw9-qpwj