TP-Link Archer BE800 V1 — Parental Control LAN RCE

CVE: CVE-2026-9254
CVSS: 8.7 (High)
Auth required: None
Network position: LAN only
Found on version 1.3.2 Build 20251015 rel.10659(5553)

Summary

The parental control blocking endpoint (/cgi-bin/luci/blocking?form=vercode) is reachable from the LAN without admin credentials. The url parameter is passed to a shell command via fork_exec(string.format("%s %s %s", BINARY, owner_id, url)) after a character deny-list check. The deny-list does not include the newline character (0x0a), allowing a newline-terminated command to be appended. Commands execute as root.

A secondary information-disclosure bug on the same endpoint allows reading the current vercode without credentials, eliminating the only piece of information that cannot be observed from the captive portal redirect URL.

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Blog Writeup

https://uploadsecurity.com/Blog/CVE-2026-16348_research.html

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Researcher

[email protected]