How severe is CVE-2018-15133?

CVE-2018-15133 has a CVSS score of 8.1/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2018-15133?

CVE-2018-15133 affects the following packages: laravel/framework (Packagist), laravel/framework (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2018-15133?

No fixed version has been published for CVE-2018-15133 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2018-15133 actively exploited in the wild?

Yes. There are 15 known exploit references for CVE-2018-15133, including 1 documented proof-of-concept exploit on Exploit-DB and 9 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2018-15133?

CVE-2018-15133 has an EPSS (Exploit Prediction Scoring System) score of 84.4%, placing it in the 99th 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. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2018-15133 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2018-15133 (Laravel Deserialization of Untrusted Data Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2024-01-16. CISA required all US federal civilian agencies to remediate this vulnerability by 2024-02-06. The required action was: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

When was CVE-2018-15133 published, and has it been updated?

CVE-2018-15133 was published on August 9, 2018 and was last updated on April 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2018-15133: Laravel Framework RCE Vulnerability (High 8.1)

EPSS Exploitation Probability

via FIRST.org ↗

84.4%probability of exploitation in next 30 days

Very High Risk99th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

2 pkgs affected

🐘laravel/framework🐘laravel/framework

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

In Laravel Framework through 5.5.40 and 5.6.x through 5.6.29, remote code execution might occur as a result of an unserialize call on a potentially untrusted X-XSRF-TOKEN value. This involves the decrypt method in Illuminate/Encryption/Encrypter.php and PendingBroadcast in gadgetchains/Laravel/RCE/3/chain.php in phpggc. The attacker must know the application key, which normally would never occur, but could happen if the attacker previously had privileged access or successfully accomplished a previous attack.

Affected Packages

2 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`laravel/framework`	all versions	No fix
🐘Packagist	`laravel/framework`	≥ 5.6.0&&< 5.6.30	5.6.30

Frequently Asked Questions

In Laravel Framework through 5.5.40 and 5.6.x through 5.6.29, remote code execution might occur as a result of an unserialize call on a potentially untrusted X-XSRF-TOKEN value. This involves the decrypt method in Illuminate/Encryption/Encrypter.php and PendingBroadcast in gadgetchains/Laravel/RCE/3/chain.php in phpggc. The attacker must know the application key, which normally would never occur, but could happen if the attacker previously had privileged access or successfully accomplished a previous attack.

O3 Security · Impact-Aware SCA

Is CVE-2018-15133 in your stack?

O3 detects CVE-2018-15133 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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