How severe is CVE-2019-11830?

CVE-2019-11830 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2019-11830?

CVE-2019-11830 affects the following packages: typo3/phar-stream-wrapper (Packagist), typo3/phar-stream-wrapper (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2019-11830?

Update typo3/phar-stream-wrapper to 2.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-11830 is resolved across your whole dependency graph.

How do I detect CVE-2019-11830 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for typo3/phar-stream-wrapper, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2019-11830 if there is no patch (or I can't update yet)?

Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

Is CVE-2019-11830 actively exploited in the wild?

No public exploit code has been indexed for CVE-2019-11830 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 is the EPSS score for CVE-2019-11830?

CVE-2019-11830 has an EPSS (Exploit Prediction Scoring System) score of 2.7%, placing it in the 86th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2019-11830?

CVE-2019-11830 is classified as Deserialization of Untrusted Data (CWE-502). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2019-11830 published, and has it been updated?

CVE-2019-11830 was published on May 9, 2019 and was last updated on October 20, 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

Not in CISA KEV

CRITICAL severity

CVE-2019-11830 — phar-stream-wrapper

CRITICAL

CVE-2019-11830 is a critical-severity (CVSS 9.8) Deserialization of Untrusted Data vulnerability in typo3/phar-stream-wrapper. A fix is available for typo3/phar-stream-wrapper — see the affected versions and patch details below.

PharStreamWrapper for Typo3 unsafe deserialization vulnerability

Also known asGHSA-3hxw-g85p-qgxm

Published

May 9, 2019

Updated

Oct 20, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Oct 29, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

2.7%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs86th percentile — riskier than 86% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

2 pkgs affected

🐘typo3/phar-stream-wrapper🐘typo3/phar-stream-wrapper

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

PharMetaDataInterceptor in the PharStreamWrapper (aka phar-stream-wrapper) package 2.x before 2.1.1 and 3.x before 3.1.1 for TYPO3 mishandles Phar stub parsing, which allows attackers to bypass a deserialization protection mechanism.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`typo3/phar-stream-wrapper`	≥ 2.0.0&&< 2.1.1	2.1.1`composer require typo3/phar-stream-wrapper:^2.1.1`
🐘Packagist	`typo3/phar-stream-wrapper`	≥ 3.0.0&&< 3.1.1	3.1.1`composer require typo3/phar-stream-wrapper:^3.1.1`

Affected Products

1 product · 2 configurations

Application

pharstreamwrappertypo3

≥ 3.0.0 && < 3.1.1

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for typo3/phar-stream-wrapper, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update typo3/phar-stream-wrapper to 2.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-11830 is resolved across your whole dependency graph.
Workarounds
Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

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