Security Resilience

CVE-2026-71921

RCE

Public PoCRCECommand Injection
Published
24 August 2026
Modified
13 October 2026
CVSS Score v4 9.3
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/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 0.028 86th percentile
Risk Priority 51 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). EPSS, Forum of Incident Response and Security Teams (FIRST), epss.first.org. Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-71921 is a critical-severity OS Command Injection (CWE-78) vulnerability in Draytek (inferred from references). Its CVSS base score is 9.3 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 14% of CVEs by exploit likelihood; 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 SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

Multiple DrayTek VigorSwitch models contain a pre-authentication command injection vulnerability in the setget.cgi interface. The vulnerability is caused by insufficient filtering of the pass field before command execution. A remote attacker can trigger this vulnerability via crafted input to execute…

more

arbitrary commands with root privileges.

CWE(s)
CWE-78

Related Threats

MITRE ATT&CK Enterprise Techniques

MITRE ATT&CK v20.0

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
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 →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1548.001 Setuid and Setgid Privilege Escalation
An adversary may abuse configurations where an application has the setuid or setgid bits set in order to get code running in a different (and possibly more privileged) user’s context.
attack.mitre.org →
T1584.004 Server Resource Development
Adversaries may compromise third-party servers that can be used during targeting.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-33013Shared CWE-78
CVE-2025-32002Shared CWE-78
CVE-2023-25395Shared CWE-78
CVE-2023-42788Shared CWE-78
CVE-2026-52483Shared CWE-78
CVE-2024-37391Shared CWE-78
CVE-2024-50371Shared CWE-78
CVE-2026-72875Shared CWE-78
CVE-2025-65791Shared CWE-78
CVE-2026-79766Shared CWE-78

Affected Assets

Draytek
—
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.2.5
  • V1.2.8

Mitigating Controls (NIST 800-53 r5)

Our mappings, made for this CVE.

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation can discover missing or incorrect command sanitization during development.

SI-10 Information Input Validation good match

Input validation directly neutralizes or rejects special characters that would otherwise alter OS command structure.

AC-6 Least Privilege partial match

Least privilege reduces the permissions available to any process that could be subverted by injected commands.

CM-7 Least Functionality partial match

Least functionality restricts available OS commands and interpreters, limiting the blast radius of injection.

SA-8 Security and Privacy Engineering Principles partial match

Secure engineering principles require proper neutralization of untrusted input before command construction.

Mitigating Controls (NIST CSF 2.0)

Our mappings, derived directly from the weakness types (CWEs) cited in the NVD entry via our CWE→CSF cross-walk — links open the control.

PR.PS-06 mostly match
blocks

PR.PS-06's SDLC practices directly require secure coding and input handling that blocks command-injection defects, yet the single broad outcome leaves many specific neutralization vectors and verification gaps unaddressed.

PR.PS-02 partial match
blocks

Routine patching/maintenance can remediate known command-injection CVEs in dependencies (partial forward) but does nothing to stop developers from introducing improper neutralization in custom code (none reverse).

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

Our mappings, derived directly from the weakness types (CWEs) cited in the NVD entry via our CWE→ISO cross-walk — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing and code review target insecure use of operating-system command interfaces, catching command-injection flaws introduced during development.

A.8.28 Secure coding partial match
prevents

A.8.28 mandates secure coding practices (input validation, avoiding dangerous functions like system()/exec(), peer review, SAST during development) that prevent some OS command injection instances, but it is a practice-based control whose effect depends on developer skill and implementation rigor, leaving a fallible remainder that A.8.29 testing reaches more completely.

A.8.8 Management of technical vulnerabilities partial match
finds

A.8.8's reach is DISCLOSURE — it finds OS command injection only where it has been published as a CVE in a third-party component, which is a minority of instances; most CWE-78 lives in first-party code that A.8.8's published-advisory and component-inventory programme does not read.

References