What is CVE-2025-63721?

CVE-2025-63721 is a high-severity vulnerability in Hummerrisk, classified under Deserialization of Untrusted Data. CVSS score: 8.8/10. Published 2025-12-08.

How severe is CVE-2025-63721?

High severity. CVSS v3 base score is 8.8 out of 10.

Deserialization in Hummerrisk

CVE-2025-63721

HummerRisk thru v1.5.0 is using a vulnerable Snakeyaml component, allowing attackers with normal user privileges to hit the /rule/add API and thereby achieve RCE and take over the server.

Vulnerability class: Insecure Deserialization

Published 2025-12-08 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (39.8th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 39.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: +0.000

Affected products

Hummerrisk

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

References

github.com/k1ng0fic3/secrisk/blob/main/README.md (Exploit, Third Party Advisory)
gist.github.com/k1ng0fic3/e8c8c9353fff8fa95e2c2952587e9266 (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2025-63721?: CVE-2025-63721 is a high-severity vulnerability in Hummerrisk, classified under Deserialization of Untrusted Data. CVSS score: 8.8/10. Published 2025-12-08.
How severe is CVE-2025-63721?: High severity. CVSS v3 base score is 8.8 out of 10.