OS Command InjectionWeakness · CWE-78

CVE-2026-27849

CRITICAL · 9.8 CVSS v3.1 Published 2026-02-25
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Due to missing neutralization of special elements, OS commands can be injected via the update functionality of a TLS-SRP connection, which is normally used for configuring devices inside the mesh network. This issue affects MR9600: 1.0.4.205530; MX4200: 1.0.13.210200.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

OS command injection vulnerability in the update functionality of TLS-SRP connections on MR9600 (1.0.4.205530) and MX4200 (1.0.13.210200) routers. The missing neutralization of special elements allows attackers to execute arbitrary OS commands via the mesh network device configuration interface.

MitigationApply vendor-provided firmware updates as soon as available. Until then, restrict network access to the TLS-SRP management interface and monitor for suspicious update activity.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify device model
    Access the device admin interface or check the device label/documentation to confirm the exact model number is MR9600 or MX4200
    Affected if Device model is MR9600 or MX4200
  2. Check installed firmware version
    Log into the mesh router admin panel (typically via web UI at the gateway IP) and navigate to Settings > Firmware or System > Status to view the current firmware version
    Affected if Firmware version has not been patched by the vendor (no patched version range was specified in the CVE)
  3. Confirm TLS-SRP feature is enabled
    In the admin interface, look for TLS-SRP settings under Wireless > Mesh Settings, Network > Mesh Configuration, or Security settings. Check if the feature is actively configured for intra-mesh communication
    Affected if TLS-SRP is enabled and used for mesh configuration updates
  4. Verify network exposure of management interface
    Check router firewall rules or port forwarding settings to determine if the mesh management interface (ports typically used for TLS-SRP) is accessible from untrusted network segments or the internet
    Affected if TLS-SRP management interface is exposed to untrusted networks or the internet
  5. Inspect for suspicious command injection indicators
    Review system logs, audit logs, or shell history (if accessible via diagnostic tools) for unexpected commands, unfamiliar processes, or outbound connections originating from the mesh device
    Affected if Unusual commands or processes appear in logs, suggesting potential exploitation

You are likely affected if you operate an MR9600 or MX4200 mesh device with TLS-SRP enabled for intra-mesh updates, regardless of firmware version until a patch is confirmed by the vendor.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply vendor-provided firmware updates as soon as available. Until then, restrict network access to the TLS-SRP management interface and monitor for suspicious update activity.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-27849 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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