RCE in MediaWiki

CVE-2026-8857

A vulnerability in Wikimedia Foundation timeline. This vulnerability is associated with program files scripts/EasyTimeline.Pl, includes/Timeline.Php. This issue affects timeline: from * before 1.46.0, 1.45.4, 1.44.6, 1.43.9.

Vulnerability class: RCE (Remote Code Execution)

Published · last modified .

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: 0.021 (81.0th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 81st percentile — 81.0% 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-2026-8857: held from 0.021 to 0.021.

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

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-8857?
CVE-2026-8857 is a high-severity vulnerability in MediaWiki, classified under Code Injection. CVSS score: 8.8/10. Published 2026-07-01.
How severe is CVE-2026-8857?
High severity. CVSS v3 base score is 8.8 out of 10.