criticalCVSS 9.8Vulnerability

CVE-2026-54133

## 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 `JP_PHP_COMPILE` 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 file. 7. The injected PHP executes in the context of the affected application. In that flow, an attacker can execute arbitrary PHP code with the privileges of the PHP process. The searched data document is not sufficient to exploit this issue by itself; the attacker must be able to influence the JMESPath expression string. The default runtime used by `JmesPath\search()` is `AstRuntime`, which interprets the parsed expression tree and is not affected unless `JP_PHP_COMPILE` is enabled. Applications are most likely to be affected when they explicitly instantiate `JmesPath\CompilerRuntime`, enable `JP_PHP_COMPILE` as a performance optimization, and allow users to provide JMESPath expressions for filtering, querying, or transforming data. ## Patches The issue is patched in `2.9.1` and later. ## Workarounds If you cannot upgrade immediately, disable `JP_PHP_COMPILE` and do not use `JmesPath\CompilerRuntime` with attacker-controlled expressions. Use the default `AstRunti

Properties

ghsa_id
GHSA-pcw8-m77r-2528
severity
critical
summary
jmespath.php has CompilerRuntime code injection via unescaped function names
cvss_score
9.8
cve_id
CVE-2026-54133
cvss_vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
is_ghsa_only
false
ghsa_published
2026-08-18T20:16:38Z
source_url
https://github.com/advisories/GHSA-pcw8-m77r-2528
ghsa_updated
2026-08-18T20:16:40Z

Related Entities (6)

HAS_WEAKNESS (3)

[Weakness]Improper Control of Generation of Code ('Code Injection')
[Weakness]Improper Input Validation
[Weakness]Improper Encoding or Escaping of Output

REPORTED_BY (1)

[Source]GitHub Advisory Database

VULNERABLE_TO (1)

[Software]composer/mtdowling/jmespath.php

AFFECTS (1)

[Software]composer/mtdowling/jmespath.php

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CVE-2026-54133 (CVSS 9.8) — Ninja Signal Threat Intelligence | Ninja Signal