Auth bypass in Bookly

CVE-2026-86837

The Bookly WordPress plugin before 28.3 does not properly verify a customer's identity before updating their stored details, allowing unauthenticated attackers who know a customer's primary identifier to overwrite that customer's stored personal information such as name, email and address.

Vulnerability class: IDOR (Insecure Direct Object Reference)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (10.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 11th percentile — 10.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-86837: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

  • Bookly

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-86837?
CVE-2026-86837 is a medium-severity vulnerability in Bookly, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 5.3/10. Published 2026-09-25.
How severe is CVE-2026-86837?
Medium severity. CVSS v3 base score is 5.3 out of 10.