A vulnerability was detected in classroombookings up to 2.17.0. This impacts the function read of the file crbs-core/application/views/layout.php of the component User Display Name Handler. The manipulation of the argument displayname results in cross site scripting. The attack can be executed remotely. The exploit is now public and may be used. Upgrading to version 2.17.1 will fix this issue. The patch is identified as 69c3c9bb8a17f1ea572d8f4502bf238f0214c98a. It is suggested to upgrade the affected component. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.
https://vuldb.com/vuln/358027/cti
https://vuldb.com/submit/786154
https://github.com/sudo-secure/security-research/blob/main/classroombookings/stored-xss/PoC.md
https://github.com/classroombookings/classroombookings/releases/tag/v2.17.1
https://github.com/classroombookings/classroombookings/pull/83
Published: 2026-04-17
Updated: 2026-04-17
Base Score: 4
Vector: CVSS2#AV:N/AC:L/Au:S/C:N/I:P/A:N
Severity: Medium
Base Score: 3.5
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N
Severity: Low
Base Score: 5.1
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Severity: Medium