CVE-2026-49859
MEDIUM severity · CVSS 5.2 · CWE-693
5.2CVSS MEDIUM
Summary
Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.8.1, when fetch() was called, 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.
Impact & exploitability
Attack vectorLocal
Attack complexityLow
Privileges requiredLow
User interactionNone
Confidentiality impactLow
Integrity impactLow
Availability impactNone
Exploit probability (EPSS)0%
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
Affected products we track (1)
Recommendation
Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.