CVE-2026-49860
Deno: WebSocket API sandbox bypass via missing post-DNS check
Description
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.
No summary for this CVE yet.
CVSS Vector Breakdown
Exploitability
AV:LAttack VectorLocal
AC:LAttack ComplexityLow
PR:LPrivileges RequiredLow
UI:NUser InteractionNone
Scope
S:CScopeChanged
Impact
C:LConfidentialityLow
I:LIntegrityLow
A:NAvailabilityNone
Weaknesses
Affected Products
Exploitability
Official Patch Available
Attack Graph
Products CVE Techniques Tactics
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MITRE ATT&CK
2 techniques Command and Control
Initial Access
References
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