CVE-2026-9431
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 · uneditedA vulnerability was identified in Tenda F1202 1.2.0.20(408). This affects the function fromPptpUserAdd of the file /goform/PptpUserAdd. The manipulation of the argument opttype leads to stack-based buffer overflow. The attack can be initiated remotely. The exploit is publicly available and might be used.
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 confidenceA stack-based buffer overflow vulnerability exists in the Tenda F1202 router firmware (v1.2.0.20(408)) in the /goform/PptpUserAdd endpoint. The fromPptpUserAdd function fails to properly validate the opttype argument length before copying it to a fixed-size stack buffer, allowing remote attackers to overwrite return addresses and potentially execute arbitrary code.
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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/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 checksWork through these to decide whether this CVE applies to you.
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Identify the router modelCheck the device label or login to the admin interface and look for the model number in the system status or device info pageAffected if The device is a Tenda F1202 router
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Check the firmware versionIn the router admin interface, navigate to System Setup or Firmware Upgrade section to view the current firmware version; alternatively, check via telnet/SSH if available using 'cat /proc/version' or '固件版本' in the status pageAffected if The firmware version is 1.2.0.20(408)
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Verify the PPTP user management feature existsAccess the router web interface and look for VPN, PPTP, or User Management settings; the vulnerable endpoint is /goform/PptpUserAdd - check if this page or related PPTP user configuration is presentAffected if The PPTP user management interface is accessible and the fromPptpUserAdd function exists on the device
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Confirm remote access to the management interfaceCheck if the router admin interface is exposed to the WAN/internet by testing access to port 80/443 from an external network, or review firewall/NAT rules on upstream devicesAffected if The router's web management interface is reachable from WAN or untrusted networks
You are affected if you have a Tenda F1202 router running firmware version 1.2.0.20(408) with the PPTP user management feature exposed to network-accessible attackers.
Generated from the published advisory. Verify against your own configuration.
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 dataApply vendor firmware patch when available; until then, disable PPTP functionality on the device if unnecessary, restrict network access to the router's web interface, and monitor for indicators of compromise.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-9431 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-9431 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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