What is CVE-2026-23836?

CVE-2026-23836 is a critical-severity vulnerability in Hotcrp, classified under Improper Input Validation. CVSS score: 9.9/10. Published 2026-01-19.

How severe is CVE-2026-23836?

Critical severity. CVSS v3 base score is 9.9 out of 10.

Improper input validation in Hotcrp

CVE-2026-23836

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.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published 2026-01-19 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (36.5th percentile), scored 2026-10-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 36.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000

Affected products

Hotcrp
Kohler Hotcrp — versions = 3.1

Weakness classification (CWE)

CWE-20 — Improper Input Validation

References

github.com/kohler/hotcrp/security/advisories/GHSA-hpqh-j6qx-x57h (Patch, Vendor Advisory)
github.com/kohler/hotcrp/commit/4674fcfbb76511072a1145dad620756fc1d4b4e9 (Patch)
github.com/kohler/hotcrp/commit/bfc7e0db15df6ed6d544a639020d2ce05a5f0834 (Patch)

Frequently asked questions

What is CVE-2026-23836?: CVE-2026-23836 is a critical-severity vulnerability in Hotcrp, classified under Improper Input Validation. CVSS score: 9.9/10. Published 2026-01-19.
How severe is CVE-2026-23836?: Critical severity. CVSS v3 base score is 9.9 out of 10.