# CVE-2026-54133: jmespath.php has CompilerRuntime code injection via unescaped function names

> Attackers can execute arbitrary PHP code via crafted JMESPath expressions when using the CompilerRuntime component in jmespath.php.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Jun 2026
- **Updated:** 12 Jun 2026
- **Also known as:** CLSA-2026-1793201827, GHSA-pcw8-m77r-2528, MINI-23f5-75j5-f23q, MINI-66wp-qgjx-pq38, MINI-7fv4-6f4g-vgm4, MINI-gg33-827h-29hg, MINI-vvcw-vjgq-32cx, MINI-xjq7-53q2-2765, MINI-xrmq-v97g-g799, ROOT-APP-COMPOSER-CVE-2026-54133

## What is CVE-2026-54133?

CVE-2026-54133 is a critical code injection vulnerability in jmespath.php, published on 12 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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.

Weakness: CWE-94 (Improper Control of Generation of Code), CWE-20 (Improper Input Validation), CWE-116 (Improper Encoding or Escaping of Output)

## Which versions are affected by CVE-2026-54133?

2 open source packages ship an affected version, including mtdowling/jmespath.php. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `mtdowling/jmespath.php` | Packagist | All versions | 2.9.1 |
| `mtdowling/jmespath.php` | Packagist | All versions | 2.9.1 |

Products: Jmespath Jmespath.

## How do I fix CVE-2026-54133?

Upgrade mtdowling/jmespath.php to 2.9.1 or later.

## Is CVE-2026-54133 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-54133 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-54133 and fix it if it is affected.

What it is: CVE-2026-54133 is a critical code injection vulnerability in jmespath.php, published on 12 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-54133 exists.

Affected packages and fixed versions:
- mtdowling/jmespath.php (Packagist): affected all versions; fixed in 2.9.1
- mtdowling/jmespath.php (Packagist): affected all versions; fixed in 2.9.1

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-54133/ (Markdown: https://insights.sbomify.com/CVE-2026-54133/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-54133
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-54133
- OSV: https://osv.dev/vulnerability/CVE-2026-54133

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-54133/
Summaries are generated and may contain mistakes; the official description above is the record.