Cross Site Scripting Vulnerability in FastAdmin User Controller
CVE-2026-86244

5.3MEDIUM

Key Information:

Vendor

FastAdmin

Status
Fastadmin
Vendor
CVE Published:
7 September 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-86244?

A security vulnerability exists in the FastAdmin User Controller, specifically in the register/login functionality within the User.php file. This flaw permits attackers to manipulate the URL argument, which can lead to cross site scripting (XSS). The vulnerability is remotely exploitable and poses a significant risk if left unaddressed. It is crucial to update to version 1.2.1.20210731_beta, which includes a patch identified by the commit b3d32e2bf3637488cfe2fc58a27a9d2475b2b51b, to mitigate the risks associated with this vulnerability.

Affected Version(s)

FastAdmin 1.2.0.20210401_beta

FastAdmin 1.2.1.20210731_beta

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-86244 - Proof of Concept

References

https://vuldb.com/vuln/399399
vdb-entrytechnical-description
https://vuldb.com/vuln/399399/cti
signaturepermissions-required
https://vuldb.com/cve/CVE-2026-86244
third-party-advisory

CVSS V4

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

zzl08 (VulDB User)
.