CVE-2026-23836 is a critical remote code execution vulnerability affecting HotCRP version 3.1, a widely used conference review management software. The root cause is improper input validation (CWE-20) in the formula processing component introduced in April 2024. Specifically, the software inadequately sanitizes user-supplied input used in generating PHP code for formulas, enabling authenticated users to inject and execute arbitrary PHP commands on the server. This vulnerability requires low attack complexity and no user interaction but does require authenticated access, which is typical for conference reviewers or administrators. The vulnerability impacts confidentiality, integrity, and availability severely, as arbitrary code execution can lead to full system compromise. The vendor addressed the issue in version 3.2 by correcting input validation and sanitization mechanisms. Although no exploits have been reported in the wild yet, the criticality and ease of exploitation make this a high-risk vulnerability for organizations using the affected version. HotCRP is commonly deployed in academic and research institutions for managing peer reviews and conference submissions, making the integrity and confidentiality of data paramount.

For European organizations, especially universities, research institutes, and conference organizers relying on HotCRP 3.1, this vulnerability poses a severe risk. Exploitation could lead to unauthorized disclosure of sensitive research data, manipulation or deletion of peer review content, and disruption of conference workflows. Attackers gaining arbitrary code execution could pivot within the network, escalate privileges, and compromise additional systems. The impact extends beyond data loss to reputational damage and potential regulatory consequences under GDPR due to exposure of personal data. The criticality of this vulnerability demands immediate attention to prevent exploitation that could undermine academic integrity and operational continuity.

1. Immediate upgrade to HotCRP version 3.2 or later, which contains the patch for this vulnerability. 2. Restrict HotCRP access to trusted and verified users only, minimizing the attack surface. 3. Implement network segmentation and firewall rules to limit external access to HotCRP servers. 4. Monitor logs for unusual activity related to formula submissions or PHP execution attempts. 5. Conduct regular security audits and vulnerability scans on conference management infrastructure. 6. Educate users about the risks of submitting untrusted input and enforce strong authentication mechanisms. 7. If upgrading immediately is not feasible, consider disabling formula features or applying temporary input validation controls at the web application firewall level.