Cyber Resilience

CVE-2025-48934

Info Disclosure in Deno ≤ 2.1.13

Public PoCInfo Disclosure
Published
04 June 2025
Modified
17 June 2026
Patch / advisory
View advisory
CVSS Score v4 5.5
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0037 30th percentile
Risk Priority 38 floored blend · peak EPSS

Summary

CVE-2025-48934 is a medium-severity Insertion of Sensitive Information Into Sent Data (CWE-201) vulnerability in Deno Deno. Its CVSS base score is 5.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Network Sniffing (T1040); ranked at the 30th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A01:2025 Broken Access Control

EU & UK References

Vulnerability Data

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to versions 2.1.13 and 2.2.13, the `Deno.env.toObject` method ignores any variables listed in the `--deny-env` option of the `deno run` command. When looking at the documentation of the `--deny-env` option this…

more

might lead to a false impression that variables listed in the option are impossible to read. Software relying on the combination of both flags to allow access to most environment variables except a few sensitive ones will be vulnerable to malicious code trying to steal secrets using the `Deno.env.toObject()` method. Versions 2.1.13 and 2.2.13 contains a patch.

CWE(s)
CWE-201

Related Threats

MITRE ATT&CK Enterprise Techniques

T1040 Network Sniffing Credential Access
Adversaries may passively sniff network traffic to capture information about an environment, including authentication material passed over the network.
attack.mitre.org →
T1557 Adversary-in-the-Middle Credential Access
Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as [Network Sniffing](https://attack.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-44726Same product: Deno Deno
CVE-2026-49859Same product: Deno Deno
CVE-2024-34346Same product: Deno Deno
CVE-2025-48935Same product: Deno Deno
CVE-2023-28446Same product: Deno Deno
CVE-2023-26103Same product: Deno Deno
CVE-2024-27931Same product: Deno Deno
CVE-2025-61785Same product: Deno Deno
CVE-2024-27933Same product: Deno Deno
CVE-2026-49411Same product: Deno Deno

Affected Assets

deno
deno
≤ 2.1.13 · 2.2.0 — 2.2.13

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 1 hardening rule · 1 OS baseline
Validate
Prove the fix (OWASP ASVS)
  • V14.2.3

Mitigating Controls (NIST 800-53 r5) AI

AC-4 Information Flow Enforcement good match

Directly enforces policy-based information flow rules that block transmission of sensitive data to unauthorized actors.

AC-3 Access Enforcement good match

Enforces authorizations on logical access so that sensitive data is not released to unauthorized recipients.

SI-15 Information Output Filtering good match

Requires validation of outbound information to ensure sensitive content is not disclosed in responses or messages.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly prevent insertion of sensitive data into application outputs and messages.

DE.CM-09 partial match
prevents

Monitoring runtime data flows and outputs can detect sensitive data being transmitted.

PR.DS-02 partial match
prevents

Protecting data-in-transit can include filtering or encrypting to avoid exposing sensitive content.

PR.DS-10 partial match
prevents

Protecting data-in-use includes removing confidential values before they are processed or sent.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.11 Data masking mostly match
prevents

Data-masking techniques can prevent sensitive values from appearing in transmitted payloads.

A.5.12 Classification of information partial match
mitigates

Classification identifies sensitive data so it is not inadvertently transmitted.

A.5.13 Labelling of information partial match
mitigates

Labelling makes sensitive data visible to developers and prevents accidental inclusion in outbound messages.

A.5.14 Information transfer partial match
mitigates

Information-transfer rules directly govern what data may be sent to external parties.

A.5.34 Privacy and protection of PII partial match
mitigates

PII-protection requirements reduce the chance of sending personal data to unauthorized recipients.

A.8.12 Data leakage prevention partial match
mitigates

DLP controls inspect and block outbound flows that contain sensitive information.

References