What is CVE-2018-17857?

CVE-2018-17857 is a medium-severity vulnerability in Joomla Joomla\!, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2018-10-09.

How severe is CVE-2018-17857?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Auth bypass in Joomla Joomla\!

CVE-2018-17857

An issue was discovered in Joomla! before 3.8.13. Inadequate checks on the tags search fields can lead to an access level violation.

Vulnerability class: Broken Access Control

Published 2018-10-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.012 (66.5th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 67th percentile — 66.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000

Affected products

Joomla Joomla\!

Weakness classification (CWE)

CWE-863 — Incorrect Authorization

References

www.securityfocus.com/bid/105559 (VDB Entry, Third Party Advisory, vdb-entry)
www.securitytracker.com/id/1041914 (VDB Entry, Third Party Advisory, vdb-entry)
developer.joomla.org/security-centre/753-20181003-core-access-level-violation-i… (Vendor Advisory)

Frequently asked questions

What is CVE-2018-17857?: CVE-2018-17857 is a medium-severity vulnerability in Joomla Joomla\!, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2018-10-09.
How severe is CVE-2018-17857?: Medium severity. CVSS v3 base score is 4.3 out of 10.