What is CVE-2018-12071?

CVE-2018-12071 is a critical-severity vulnerability in Codeigniter, classified under Session Fixation. CVSS score: 9.8/10. Published 2018-06-17.

How severe is CVE-2018-12071?

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

Vulnerability in Codeigniter

CVE-2018-12071

A Session Fixation issue exists in CodeIgniter before 3.1.9 because session.use_strict_mode in the Session Library was mishandled.

Published 2018-06-17 · 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: 0.015 (73.3th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 73rd percentile — 73.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.015 · newest: 0.015 · change: 0.000

Affected products

Codeigniter

Weakness classification (CWE)

CWE-384 — Session Fixation

References

www.codeigniter.com/user_guide/changelog.html (Release Notes, Vendor Advisory)
github.com/bcit-ci/CodeIgniter/commit/800a20d6c4662d99ae0988b2f8f2238bb8bb29db

Frequently asked questions

What is CVE-2018-12071?: CVE-2018-12071 is a critical-severity vulnerability in Codeigniter, classified under Session Fixation. CVSS score: 9.8/10. Published 2018-06-17.
How severe is CVE-2018-12071?: Critical severity. CVSS v3 base score is 9.8 out of 10.