typo3/cms-core security advisory

CVE-2026-47348: TYPO3-CORE-SA-2026-010: Cross-Site Scripting in Indexed Search

CVE-2026-47348 is a medium-severity XSS vulnerability in the PHP package typo3/cms-core (CVSS 5.1), published 9 June 2026. It is fixed in 13.4.31 and 14.3.3, one per release line; earlier versions on each line are affected. Exploiting it needs a low-privilege user account.

medium 5.1 published 2026-06-09 · updated 2026-07-23

Affected versions: >= 13.0.0, < 13.4.31
>= 14.0.0, < 14.3.3
Fixed in: 13.4.31, 14.3.3
Newest release: 14.3.10
Severity: Medium · CVSS 5.1
Type: Cross-site scripting (XSS)
CWE-79
Exploited in the wild: Not on the CISA KEV list
checked 2026-11-04

Is your typo3/cms-core version affected?

Run composer show typo3/cms-core in your project, then enter the version. We check it against this and every other known typo3/cms-core advisory.

Who can exploit CVE-2026-47348

Access: A normal, low-privilege user account in the app.
Interaction: A user also has to do something, such as open a link or a page the attacker prepared.

CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:N/SI:L/SA:N

Your app is only exposed if it uses the affected part of typo3/cms-core. The advisory below says which part that is. If you are not sure, upgrade anyway: it costs less than finding out.

How to fix CVE-2026-47348 in typo3/cms-core

Find the installed version: composer show typo3/cms-core. If you never required it yourself, composer why typo3/cms-core shows which package pulls it in.
Update it: composer update typo3/cms-core --with-all-dependencies. You need the fixed version for your release line (13.4.31 and 14.3.3).
If Composer will not go that high, your composer.json constraint is holding it back. Widen it (for example "typo3/cms-core": "^14.3.3" if you can take that version), or upgrade the package that requires it.
Run composer audit. It reads the same advisory data and should no longer list CVE-2026-47348.
Commit composer.lock and deploy it. On the server, run composer install --no-dev from the lock file, not composer update.

If you cannot upgrade yet

General hardening for XSS issues while the upgrade waits. None of it replaces the fix.

Escape output in your own templates and add a Content-Security-Policy that blocks inline scripts.
Limit who can save the content the advisory names (for example rich text, SVG or form fields).
If your app does not use the affected feature, note that in your audit, but still plan the upgrade.

The CVE-2026-47348 advisory

Editors with access to create or modify page content were able to include HTML markup in page titles that were stored in the search index without sanitization. When displayed in frontend search results via the Indexed Search plugin, these titles were rendered without proper output encoding, resulting in a Cross-Site Scripting vulnerability. This issue affects TYPO3 CMS versions 13.0.0-13.4.30 and 14.0.0-14.3.2.

Description from the CVE record, via the NVD entry for CVE-2026-47348. Advisory title: “TYPO3-CORE-SA-2026-010: Cross-Site Scripting in Indexed Search”.

References

Other typo3/cms-core advisories

high CVE-2026-19418: TYPO3-CORE-SA-2026-021: Broken Access Control in Backend and Install Tool 2026-08-11
high CVE-2026-11607: TYPO3-CORE-SA-2026-019: Broken Access Control in Form Framework 2026-06-09
medium CVE-2026-49740: TYPO3-CORE-SA-2026-018: Insecure Deserialization in Core API 2026-06-09
high CVE-2026-49741: TYPO3-CORE-SA-2026-017: Privilege Escalation & SQL Injection in Form Framework 2026-06-09
low CVE-2026-49738: TYPO3-CORE-SA-2026-016: Broken Access Control in File Abstraction Layer 2026-06-09
medium CVE-2026-47352: TYPO3-CORE-SA-2026-015: Broken Access Control in Backend API 2026-06-09

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Where this data comes from

Affected and fixed versions: the Packagist security advisories API (GitHub Advisory Database and FriendsOfPHP), the same data composer audit uses. Synced 2026-11-03.
Description, score, weakness and references: NIST National Vulnerability Database (NVD), checked 2026-11-04. This product uses data from the NVD API but is not endorsed or certified by the NVD.
Exploited-in-the-wild status: the CISA Known Exploited Vulnerabilities catalog, checked 2026-11-04.
Compiled by Daniel Lasek at Laskyr from the sources above. The summary, “who can exploit it”, “how to fix it” and hardening sections are our plain-English reading of the record and are generated from it. The quoted description is the record's own text. Spot an error? Tell us.