Deno Node TCPWrap numeric hostname aliases bypass --deny-net resolved-IP deny checks

published 2026-06-16 4 mo ago modified 2026-10-25 14 d ago also EUVD-2026-38544 , GHSA-v8fw-85r8-5m23

cvss: 6.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits: 0; none known

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.8.0, the Node.js compatibility TCP path checked the permission against the original hostname string before resolution and then did not re-check after resolution. A caller could therefore pass a numeric alias of an IP address (for example the decimal integer 2130706433 or the hex form 0x7f000001, both of which resolve to 127.0.0.1) and reach the denied destination through node:net.connect or node:http.request's { host, port } options form. This vulnerability is fixed in 2.8.0.

Patch / fix

fixed in 4

crates.io deno 2.8.0
deno deno 2.8.0
deno deno_runtime 2.8.0
deno serde_v8 2.8.0

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 4 mo ago (2026-06-26)

Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/denoland/deno/security/advisories/GHSA-v8fw-85r8-5m23 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	6.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
GitHub	3.1	6.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

Affected packages

ecosystem	package	affected	fixed in
crates.io	deno	<2.8.0	2.8.0

Affected products

denoland deno

Classification

Weakness

CWE-284 Improper Access Control

References

github.com /denoland/deno/security/advisories/GHSA-v8fw-85r8-5m23
exploit, web, mitigation, third-party-advisory
nvd.nist.gov /vuln/detail/CVE-2026-49411
advisory
github.com /denoland/deno
package

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary