PatchSiren cyber security CVE debrief
CVE-2026-9421 KLiK CVE debrief
A medium-severity unrestricted file upload vulnerability exists in KLiK SocialMediaWebsite 1.0, specifically within the `uniqid` function of `upload.inc.php`. The vulnerability allows remote attackers to upload arbitrary files without proper validation, potentially enabling code execution or other malicious activities. The exploit has been publicly disclosed and is actively exploitable. The CVSS 4.0 vector indicates network attack vector with low attack complexity, no privileges required, and no user interaction needed, with partial impacts to confidentiality, integrity, and availability. The vulnerability is associated with CWE-284 (Improper Access Control) and CWE-434 (Unrestricted Upload of File with Dangerous Type).
- Vendor
- KLiK
- Product
- SocialMediaWebsite
- CVSS
- MEDIUM 5.5
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-05-25
- Original CVE updated
- 2026-05-26
- Advisory published
- 2026-05-25
- Advisory updated
- 2026-05-26
Who should care
System administrators running KLiK SocialMediaWebsite 1.0, web application security teams, and organizations using this social media platform software
Technical summary
The vulnerability resides in the `uniqid` function within `upload.inc.php` of KLiK SocialMediaWebsite 1.0. Insufficient validation of uploaded files permits unrestricted file uploads, allowing remote attackers to upload potentially executable content. The attack requires no authentication or user interaction and can be conducted over the network.
Defensive priority
medium
Recommended defensive actions
- Review and restrict file upload functionality in upload.inc.php, implementing strict file type validation and content inspection
- Apply principle of least privilege to file upload directories, ensuring uploaded files cannot be executed
- Consider implementing file renaming and storage outside web root to prevent direct access
- Monitor for indicators of compromise related to unauthorized file uploads
- Verify vendor identification and seek official patch from KLiK SocialMediaWebsite maintainers
Evidence notes
Vulnerability identified in KLiK SocialMediaWebsite 1.0 file upload component. Public exploit availability confirmed. CVE published 2026-05-25, modified 2026-05-26. Vendor attribution marked as low confidence requiring review.
Official resources
public