Cyber Resilience

CVE-2026-49401

HighPublic PoC

Published: 23 June 2026

Published
23 June 2026
Modified
26 June 2026
KEV Added
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Patch
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CVSS Score v3.1 7.3 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:N
EPSS Score 0.0014 4.1th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-49401 is a high-severity Improper Resolution of Path Equivalence (CWE-41) vulnerability in Deno Deno. Its CVSS base score is 7.3 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Data from Local System (T1005); ranked at the 4.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.14, Deno's permission system enforces filesystem and execution restrictions by comparing the requested path against the path supplied to --deny-read, --deny-write, --deny-run, or --deny-ffi. On macOS, that comparison was done…

more

at the raw-byte level while the APFS filesystem treats different Unicode spellings of the same name as the same file. That means a program could reach a denied path by spelling it differently than the deny rule. This vulnerability is fixed in 2.7.14.

CWE(s)
CWE-41CWE-176

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
attack.mitre.org →
T1083 File and Directory Discovery Discovery
Adversaries may enumerate files and directories or may search in specific locations of a host or network share for certain information within a file system.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
Why these techniques?

Path permission bypass via Unicode normalization enables unauthorized local file access/discovery and can be leveraged against apps using Deno permissions.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

Affected Assets

deno
deno
≤ 2.7.14

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References