CVE-2026-54133·PHP vulnerability
jmespath.php allows users to use JMESPath, software for declaratively specifying how to extract elements from a JSON document, in PHP applications with PHP data structures. Versions prior to 2.9.1 can generate and execute attacker-controlled PHP code when `JmesPath\CompilerRuntime` is used with an attacker-controlled JMESPath expression. The compiler emits parsed JMESPath function names into generated PHP source without sufficient escaping. A crafted expression can cause the generated cache file to contain executable attacker-controlled PHP, which is then loaded by the compiler runtime. The issue is patched in `2.9.1` and later. As a workaround, disable `JP_PHP_COMPILE` and do not use `JmesPath\CompilerRuntime` with attacker-controlled expressions. Use the default `AstRuntime` for untrusted expressions. Applications that must continue accepting untrusted JMESPath expressions before upgrading should ensure those expressions are never evaluated by the compiler runtime.
- Severity
- critical
- Software
- PHP
- Fixed in
- 2.9.1
- Published
- 2026-06-12
Affected versions
Until: 2.9.1
Fixed in: 2.9.1
How to fix this CVE
Update PHP and the jmespath.php library to version 2.9.1 or later to patch a critical remote code execution vulnerability in the JMESPath compiler runtime. If you cannot update immediately, disable the JP_PHP_COMPILE flag and use the default AstRuntime instead of CompilerRuntime when processing untrusted JMESPath expressions. This prevents malicious expressions from being compiled into executable PHP code stored in cache files.
sudo dnf update php php-common php-cli php-fpmDefensia detects this vulnerability
How to check if you are affected
- Run `php -v` to check the current PHP version installed on the system
- If using Composer, run `composer show jmespath/jmespath` to verify the installed jmespath.php version and confirm it is below 2.9.1
- Search application logs for stack traces containing 'JmesPath\CompilerRuntime' or 'JP_PHP_COMPILE' to identify if the vulnerable runtime is actively in use
- Check the PHP temporary or cache directory (typically `/tmp`, `/var/tmp`, or configured cache path) for recently modified `.php` files with suspicious content or unfamiliar function names in the filename
FAQ
What is CVE-2026-54133?
This vulnerability allows attackers to execute arbitrary PHP code by crafting malicious JMESPath expressions that exploit insufficient escaping in the jmespath.php compiler. When the vulnerable CompilerRuntime processes untrusted expressions, it generates PHP cache files containing attacker-controlled code that gets loaded and executed.
Is CVE-2026-54133 being actively exploited?
According to CISA records, CVE-2026-54133 is not currently listed as actively exploited in the wild, and no public exploit code is available. However, the critical CVSS score of 9.8 means exploitation is straightforward for attackers who discover unpatched systems.
What versions of PHP are affected by CVE-2026-54133?
The jmespath.php library in all versions prior to 2.9.1 is vulnerable. Any PHP application using jmespath.php with the CompilerRuntime and processing untrusted JMESPath expressions is at risk.
How do I check if my server is vulnerable to CVE-2026-54133?
Run `composer show jmespath/jmespath` to check the version. If it returns a version lower than 2.9.1, your application is vulnerable. Additionally, verify that JP_PHP_COMPILE is not enabled and confirm whether CompilerRuntime is used with user-supplied expressions in your application code.
Does Defensia detect CVE-2026-54133?
Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If PHP or jmespath.php is installed on a monitored server and running a vulnerable version, CVE-2026-54133 will appear in your dashboard with remediation steps.
Related PHP CVEs
References
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