What is CVE-2011-4903?

CVE-2011-4903 is a medium-severity vulnerability in TYPO3, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2019-11-06.

How severe is CVE-2011-4903?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in TYPO3

CVE-2011-4903

Cross-site Scripting (XSS) in TYPO3 before 4.3.12, 4.4.x before 4.4.9, and 4.5.x before 4.5.4 allows remote attackers to inject arbitrary web script or HTML via the RemoveXSS function.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2019-11-06 · last modified 2026-06-16.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.008 (56.0th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 56.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

TYPO3 — versions before 4.5.4

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

security-tracker.debian.org/tracker/CVE-2011-4903 (Third Party Advisory)
typo3.org/security/advisory/typo3-core-sa-2011-001/ (Vendor Advisory)

Frequently asked questions

What is CVE-2011-4903?: CVE-2011-4903 is a medium-severity vulnerability in TYPO3, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2019-11-06.
How severe is CVE-2011-4903?: Medium severity. CVSS v3 base score is 6.1 out of 10.