Is CVE-2026-103437 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-103437 being exploited in the wild.

How severe is CVE-2026-103437?

Informational severity, published 30 September 2026.

Which products and versions are affected?

Wikimedia Foundation MediaWiki ReadingLists 1.45, 1.46.

Is there a fix for CVE-2026-103437?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-103437 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-103437?

Check whether you run Wikimedia Foundation MediaWiki ReadingLists at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-103437: MediaWiki ReadingLists reflected XSS in imported URLs

CVE-2026-103437 · Severity: info · Published 2026-09-30

The Wikimedia Foundation's MediaWiki ReadingLists extension, which allows users to import reading lists from other wikis, contains a reflected cross-site scripting (XSS) vulnerability. An attacker can craft a malicious import link that executes arbitrary JavaScript in the victim's browser with their full MediaWiki session privileges, enabling account takeover, data theft, or unauthorized actions on their behalf.

Vendors: Wikimedia Foundation.

Quick answers

Is CVE-2026-103437 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-103437 being exploited in the wild.
How severe is CVE-2026-103437?: Informational severity, published 30 September 2026.
Which products and versions are affected?: Wikimedia Foundation MediaWiki ReadingLists 1.45, 1.46.
Is there a fix for CVE-2026-103437?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-103437 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-103437?: Check whether you run Wikimedia Foundation MediaWiki ReadingLists at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability exists in the web import flow where the extension accepts an attacker-controlled project URL and uses the canonicalurl returned by that server as a card link without validating its URI scheme. A named/authenticated user who opens a crafted Special:ReadingLists?limport= link and clicks the imported card will execute arbitrary JavaScript in the wiki origin. The fix requires validating imported URLs to allow only HTTP(S) schemes and rejecting javascript: or other non-standard URI schemes.

Affected products

Wikimedia Foundation MediaWiki ReadingLists 1.45, 1.46

Timeline

2026-09-30: disclosed: Published on NVD and Wikimedia Phabricator

References

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