I12 FirmwareOperating system · Tenda

CVE-2026-5849

CRITICAL · 9.8 CVSS v3.1 Published 2026-04-09
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
Public exploit 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
A vulnerability was determined in Tenda i12 1.0.0.11(3862). The impacted element is an unknown function of the component HTTP Handler. Executing a manipulation can lead to path traversal. The attack may be launched remotely. The exploit has been publicly disclosed and may be utilized.

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

A critical path traversal vulnerability exists in the HTTP Handler component of Tenda i12 router firmware version 1.0.0.11(3862). An unauthenticated remote attacker can manipulate HTTP requests to access files outside the web server's root directory, potentially exposing sensitive system files, configuration data, or credentials.

MitigationImplement strict input validation and sanitization for all file path parameters in the HTTP handler. Use allowlist validation for permitted paths and canonicalize paths to prevent traversal sequences (../). Consider applying vendor firmware updates when available.

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

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
I12 FirmwareOperating system
Affected:= 1.0.0.11\(3862\)

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 the router model
    Access the router admin interface or check the device label to confirm it is a Tenda i12 router
    Affected if The device is not a Tenda i12 model, then it is not affected by this specific CVE
  2. Check the installed firmware version
    Log into the router admin panel and navigate to System Settings > Firmware Version, or use the Tenda firmware upgrade page to view the current version
    Affected if The firmware version is exactly 1.0.0.11(3862), then it matches the affected version range
  3. Verify the HTTP handler service is active
    Check if the router web interface is accessible over HTTP/HTTPs on the LAN or WAN interface. Attempt to access the router login page via browser at the router's IP address
    Affected if The HTTP service is disabled and not accessible, the path traversal cannot be exploited even on the affected firmware
  4. Test for path traversal vulnerability in HTTP requests
    Send a crafted HTTP GET request to the router's web server with path traversal sequences such as /cgi-bin/../etc/passwd or /cgi-bin/../proc/version and observe the response
    Affected if The HTTP handler returns file contents from outside the web root directory (sensitive system files), the vulnerability is confirmed present

A user is affected if they have a Tenda i12 router running firmware version 1.0.0.11(3862) with the HTTP handler service enabled and accessible, as demonstrated by successful path traversal responses.

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

Implement strict input validation and sanitization for all file path parameters in the HTTP handler. Use allowlist validation for permitted paths and canonicalize paths to prevent traversal sequences (../). Consider applying vendor firmware updates when available.

Fix this in I12 Firmware Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,640
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Scan for this in your stack

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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-2026-5849 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
  • No spam, self-promotion, credentials, or personal data