Security Resilience

CVE-2026-9458

RCE

Published
25 May 2026
Modified
23 July 2026
CVSS Score v4 8.9
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: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 0.033 88th percentile
Risk Priority 50 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-9458 is a high-severity Command Injection (CWE-77) vulnerability in Totolink A8000RU (inferred from references). Its CVSS base score is 8.9 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked in the top 12% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

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.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

A vulnerability identified as CVE-2026-9458 affects the Totolink A8000RU router running firmware version 7.1cu.643_b20200521. It resides in the setWanCfg function within the /cgi-bin/cstecgi.cgi file of the web management interface, where improper handling of the enabled argument permits OS command injection. The issue is tracked under CWE-77 and CWE-78 and carries a CVSS 4.0 score of 8.9, reflecting network-accessible attack vectors that require no authentication or user interaction.

Remote, unauthenticated attackers can supply crafted input to the affected parameter and execute arbitrary operating system commands on the device. Successful exploitation grants full control over confidentiality, integrity, and availability of the router, with a publicly available proof-of-concept exploit already disclosed.

Reference materials include a GitHub repository containing reproduction details, multiple Vuldb entries, and the vendor website, yet none of the listed sources describe available patches, firmware updates, or specific mitigation steps. The EPSS score remains flat at 0.0125 with no observed increase after disclosure.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A vulnerability was identified in Totolink A8000RU 7.1cu.643_b20200521. The impacted element is the function setWanCfg of the file /cgi-bin/cstecgi.cgi of the component Web Management Interface. Such manipulation of the argument enabled leads to os command injection. The attack may be…

more

performed from remote. The exploit is publicly available and might be used.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
T1059.003 Windows Command Shell Execution
Adversaries may abuse the Windows command shell for execution.
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
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.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-11556Shared CWE-77, CWE-78
CVE-2026-5355Shared CWE-77, CWE-78
CVE-2026-5012Shared CWE-77, CWE-78
CVE-2025-15254Shared CWE-77, CWE-78
CVE-2026-2629Shared CWE-77, CWE-78
CVE-2026-102240Shared CWE-77, CWE-78
CVE-2026-3964Shared CWE-77, CWE-78
CVE-2026-15495Shared CWE-77, CWE-78
CVE-2025-59831Shared CWE-77, CWE-78
CVE-2026-19036Shared CWE-77, CWE-78

Affected Assets

Totolink
A8000RU
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) AI

Developer testing and evaluation can discover command-construction flaws before deployment.

Input validation directly stops construction of commands from untrusted data containing special elements.

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

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

Secure engineering principles include proper neutralization and safe command construction practices.

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
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) 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.

finds

Security testing in development catches command-injection vulnerabilities before release.

prevents

Secure coding standards require proper escaping and parameterization of commands, directly eliminating CWE-77.

Hardening callouts derived

DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.

  • No fine-grained STIG row for CWE-77, a class-level weakness, and none of its children carries one either.

References