How severe is CVE-2019-12747?

CVE-2019-12747 has a CVSS score of 8.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2019-12747?

CVE-2019-12747 affects the following packages: typo3/cms-core (Packagist), typo3/cms-core (Packagist), typo3/cms (Packagist), typo3/cms (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2019-12747?

Update typo3/cms-core to 8.7.27 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-12747 is resolved across your whole dependency graph.

How do I detect CVE-2019-12747 in my Packagist dependencies?

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

How do I mitigate CVE-2019-12747 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-2019-12747 actively exploited in the wild?

No public exploit code has been indexed for CVE-2019-12747 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-2019-12747?

CVE-2019-12747 has an EPSS (Exploit Prediction Scoring System) score of 1.6%, placing it in the 75th 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-2019-12747?

CVE-2019-12747 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-2019-12747 published, and has it been updated?

CVE-2019-12747 was published on July 9, 2019 and was last updated on October 24, 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

HIGH severity

CVE-2019-12747 — cms-core

HIGHFix: TYPO3/typo3@647aa7a

CVE-2019-12747 is a high-severity (CVSS 8.8) Deserialization of Untrusted Data vulnerability in typo3/cms-core. A fix is available for typo3/cms-core — see the affected versions and patch details below.

TYPO3 Vulnerable to Insecure Deserialization

Also known asGHSA-86hp-xrhj-fhpq

Published

Jul 9, 2019

Updated

Oct 24, 2026

Affected

4 pkgs

Patched

4 / 4

Exploits

None indexed

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

EPSS Exploitation Probability

via FIRST.org ↗

1.6%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs75th percentile — riskier than 75% 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

4 pkgs affected

🐘typo3/cms-core🐘typo3/cms-core🐘typo3/cms🐘typo3/cms

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

TYPO3 8.x through 8.7.26 and 9.x through 9.5.7 allows Deserialization of Untrusted Data.

Affected Packages

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`typo3/cms-core`	≥ 8.0.0&&< 8.7.27	8.7.27`composer require typo3/cms-core:^8.7.27`
🐘Packagist	`typo3/cms-core`	≥ 9.0.0&&< 9.5.8	9.5.8`composer require typo3/cms-core:^9.5.8`
🐘Packagist	`typo3/cms`	≥ 8.0.0&&< 8.7.27	8.7.27`composer require typo3/cms:^8.7.27`
🐘Packagist	`typo3/cms`	≥ 9.0.0&&< 9.5.8	9.5.8`composer require typo3/cms:^9.5.8`

Affected Products

1 product · 2 configurations

Application

typo3typo3

≥ 9.0.0 && ≤ 9.5.7

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/cms-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update typo3/cms-core to 8.7.27 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-12747 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

TYPO3 8.x through 8.7.26 and 9.x through 9.5.7 allows Deserialization of Untrusted Data.

O3 Security · Impact-Aware SCA

Is CVE-2019-12747 in your dependencies?

Find it across Packagist, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

8.8/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Raw vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CWE Classification

CWE-502Deserialization of Untrusted Data

Weaponization

No Nuclei template, Metasploit module or public proof-of-concept found.

OpenSSF Scorecard

Package health score

security-advisories

4.8/10

Maintained10/10

Code-Review10/10

Branch-Protection0/10

Assessed Oct 26, 2026

Timeline

Disclosed

Jul 9, 2019

Last updated

Oct 24, 2026

Identifiers

CVE-2019-12747

GHSA-86hp-xrhj-fhpq

References

Advisorytypo3.org · typo3 core sa 2019 020 Advisorynvd.nist.gov · CVE 2019 12747 Webgithub.com · CVE 2019 12747.yaml Webgithub.com · CVE 2019 12747.yaml Webtypo3.org · typo3 8 release notes Webtypo3.org · typo3 core sa 2019 020 Webgithub.com · 647aa7afa582983cddc547fa106d31e2b1ef34fe Packagegithub.com · core

Related vulnerabilities

This CVE is high severity; 3 of 8 other CVEs affecting typo3/cms-core are rated as high or higher (top: high).

CVE-2026-19418CVE-2026-47352CVE-2026-47347CVE-2026-47343CVE-2026-49740CVE-2026-47348CVE-2026-49742CVE-2026-47349

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 24, 2026

CVE-2019-12747 — cms-core

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is CVE-2019-12747 in your dependencies?