HotCRP is conference review software. A problem introduced in April 2024 in version 3.1 led to inadequately sanitized code generation for HotCRP formulas which allowed users to trigger the execution of arbitrary PHP code. The problem is patched in release version 3.2.
https://github.com/kohler/hotcrp/security/advisories/GHSA-hpqh-j6qx-x57h
https://github.com/kohler/hotcrp/commit/bfc7e0db15df6ed6d544a639020d2ce05a5f0834
https://github.com/kohler/hotcrp/commit/4674fcfbb76511072a1145dad620756fc1d4b4e9