Laravel Deserialization of Untrusted Data Vulnerability
n/a — n/a
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.
8.1
76.8%
Vector breakdown
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- Published
- Aug 9, 2018
- Modified
- Oct 21, 2025
- Added to KEV
- Jan 16, 2024
- Federal patch due
- Feb 6, 2024
CISA required action
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Weakness classification
Proof-of-concept & exploitation references
Weaponization
Public repositories whose name or description references CVE-2018-15133, found via a live GitHub search at request time. These are community-sourced signals, not a verified working exploit - cross-check each one before relying on it, and treat higher star counts and recent activity as (weak) corroboration, not proof.
No public GitHub repositories referencing CVE-2018-15133 were found at last check. Absence here is not proof no exploit exists - see the references below for vendor advisories and write-ups.
References
Frequently asked questions
What is CVE-2018-15133?
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.
How severe is CVE-2018-15133?
CVE-2018-15133 has a CVSS base score of 8.1 out of 10 (CVSS 3.1).
Is CVE-2018-15133 actively exploited in the wild?
Yes. CVE-2018-15133 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added Jan 16, 2024, meaning CISA has confirmed evidence of active exploitation.
What is the EPSS score for CVE-2018-15133?
76.8% - meaning FIRST.org's EPSS model estimates a 76.8% probability this vulnerability will be exploited in the wild within 30 days (99% percentile among all scored CVEs).
What type of vulnerability is CVE-2018-15133?
CVE-2018-15133 is classified under CWE-502 (CWE-502 Deserialization of Untrusted Data).
Cross-checked against
Impactr finds and proves whether CVE-2018-15133 - or flaws like it - are actually reachable in your own web apps and APIs, with a reproducible exploit as evidence.
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