What is CVE-2019-15321?

CVE-2019-15321 is a critical-severity vulnerability in Optiontree Project, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2019-08-22.

How severe is CVE-2019-15321?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2019-15321 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Deserialization in Optiontree Project

CVE-2019-15321

The option-tree plugin before 2.7.3 for WordPress has Object Injection because serialized classes are mishandled.

Vulnerability class: Insecure Deserialization

Published 2019-08-22 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.021 (81.4th percentile), scored 2026-09-28.

Low probability of exploitation in the next 30 days, but still tracked. 81st percentile — 81.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.021 · newest: 0.021 · change: 0.000

Affected products

Optiontree Project

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

Public proof-of-concept exploits

20142995/nuclei-templates

References

wordpress.org/plugins/option-tree/ (Release Notes)
wpvulndb.com/vulnerabilities/9600 (Third Party Advisory)

Frequently asked questions

What is CVE-2019-15321?: CVE-2019-15321 is a critical-severity vulnerability in Optiontree Project, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2019-08-22.
How severe is CVE-2019-15321?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2019-15321 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.