How severe is CVE-2016-5091?

CVE-2016-5091 has a CVSS score of 8.1/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2016-5091?

CVE-2016-5091 affects the following packages: typo3/cms-extbase (Packagist), typo3/cms-extbase (Packagist), typo3/cms-extbase (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2016-5091?

Update typo3/cms-extbase to 6.2.24 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-5091 is resolved across your whole dependency graph.

How do I detect CVE-2016-5091 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for typo3/cms-extbase. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2016-5091 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2016-5091?

O3 pinpoints whether CVE-2016-5091 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2016-5091 actively exploited in the wild?

No public exploit code has been indexed for CVE-2016-5091 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What type of vulnerability is CVE-2016-5091?

CVE-2016-5091 is classified as CWE-254 (CWE-254). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2016-5091 published, and has it been updated?

CVE-2016-5091 was published on January 23, 2017 and was last updated on August 4, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘 Packagist

CVE-2016-5091

HIGH

CVE-2016-5091 is a high-severity (CVSS 8.1) CWE-254 vulnerability in typo3/cms-extbase. O3 Security confirms whether CVE-2016-5091 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Extbase for TYPO3 allows RCE

Also known asGHSA-jxg5-35fj-ccwf

Published

Jan 23, 2017

Updated

Aug 4, 2026

Affected

3 pkgs

Patched

2 / 3

Exploits

None indexed

Real-World Exposure

3 pkgs affected

🐘typo3/cms-extbase🐘typo3/cms-extbase🐘typo3/cms-extbase

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

Extbase in TYPO3 4.3.0 before 6.2.24, 7.x before 7.6.8, and 8.1.1 allows remote attackers to obtain sensitive information or possibly execute arbitrary code via a crafted Extbase action.

Affected Packages

3 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`typo3/cms-extbase`	all versions	6.2.24
🐘Packagist	`typo3/cms-extbase`	≥ 7.0&&< 7.6.8	7.6.8
🐘Packagist	`typo3/cms-extbase`	all versions	No fix

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for typo3/cms-extbase. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update typo3/cms-extbase to 6.2.24 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-5091 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2016-5091 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2016-5091. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Extbase in TYPO3 4.3.0 before 6.2.24, 7.x before 7.6.8, and 8.1.1 allows remote attackers to obtain sensitive information or possibly execute arbitrary code via a crafted Extbase action.

O3 Security · Impact-Aware SCA

Is CVE-2016-5091 in your dependencies?

O3 detects CVE-2016-5091 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works