jmespath.php has CompilerRuntime code injection via unescaped function names

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-54133: 0.44% estimated exploitation activity in the next 30 days; percentile 38.40 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact mtdowling/jmespath.php 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. A vulnerable flow is: 1. An application accepts or constructs a JMESPath expression using attacker-controlled input. 2. The expression is evaluated with JmesPath\CompilerRuntime, or with JmesPath\search() while JPPHPCOMPILE is enabled. 3. The crafted expression uses a non-identifier value where the parser accepts a function callee. 4. The compiler writes that value into generated PHP source without safely escaping it as a PHP string literal. 5. The generated source is written to the compiled-expression cache directory. 6. CompilerRuntime loads the generated cache…

Published by the source

18 Aug 2026, 20:16 UTC

Last modified by the source

18 Aug 2026, 20:30 UTC

Source last checked

26 Oct 2026, 14:50 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-pcw8-m77r-2528

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-pcw8-m77r-2528

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-54133

Advisory: jmespath.php has CompilerRuntime code injection via unescaped function names
IDs: CVE-2026-54133, GHSA-pcw8-m77r-2528
Record: https://patchnext.com/advisories/cve-2026-54133 (revision 2, source checked 26 Oct 2026, 14:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: mtdowling/jmespath.php 2.9.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist mtdowling/jmespath.php: affected < 2.9.1; fixed in 2.9.1

## Suggested inspection (read-only)
- Packagist mtdowling/jmespath.php: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on mtdowling/jmespath.php.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-pcw8-m77r-2528 (OSV record GHSA-pcw8-m77r-2528 lists affected ranges: Packagist mtdowling/jmespath.php >=0 <2.9.1 (fixed))
- Verified: https://github.com/advisories/GHSA-pcw8-m77r-2528 (GitHub-reviewed advisory GHSA-pcw8-m77r-2528 lists affected ranges: Packagist mtdowling/jmespath.php >=0 <2.9.1)

Commands are suggestions: review each one before running it.