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.

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)

EPSS: 0.004 (31.3th percentile) — read the EPSS interpretation.

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.

Affected products

Mediawiki
Wikimedia Foundation Timeline

Weakness classification (CWE)

CWE-94 — Code Injection

References

c4f26cc8-17ff-4c99-b5e2-38fc1793eacc (Exploit, Third Party Advisory)

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.