Summary
Problem
Applications that use GeneralUtility::sanitizeLocalUrl to allow only local URLs are vulnerable to open redirect attacks if the URL is used after it has passed the aforementioned sanitization checks. This enables attackers to redirect users to external content and carry out phishing attacks.
Credits
TYPO3 CMS thanks Alexandre Romao for reporting this issue, and TYPO3 core & security team member Benjamin Franzke for fixing it.
Resources
Impact
Untrusted input controls a URL used for redirection, which can forward users to attacker-controlled sites. Typical impact: phishing and credential harvesting via a trusted domain.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Update to TYPO3 versions 10.4.57 ELTS, 11.5.51 ELTS, 12.4.46 ELTS, 13.4.31 LTS, 14.3.3 LTS that fix the problem described.
Frequently Asked Questions
- What is CVE-2026-47347? CVE-2026-47347 is a medium-severity open redirect vulnerability in typo3/cms-core (composer), affecting versions < 10.4.57. It is fixed in 10.4.57, 11.5.51, 12.4.46, 13.4.31, 14.3.3. Untrusted input controls a URL used for redirection, which can forward users to attacker-controlled sites.
- Which versions of typo3/cms-core are affected by CVE-2026-47347? typo3/cms-core (composer) versions < 10.4.57 is affected.
- Is there a fix for CVE-2026-47347? Yes. CVE-2026-47347 is fixed in 10.4.57, 11.5.51, 12.4.46, 13.4.31, 14.3.3. Upgrade to this version or later.
- Is CVE-2026-47347 exploitable, and should I be worried? Whether CVE-2026-47347 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-47347 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-47347?
- Upgrade
typo3/cms-coreto 10.4.57 or later - Upgrade
typo3/cms-coreto 11.5.51 or later - Upgrade
typo3/cms-coreto 12.4.46 or later - Upgrade
typo3/cms-coreto 13.4.31 or later - Upgrade
typo3/cms-coreto 14.3.3 or later
- Upgrade