CVE-2026-54133
Published: 12 June 2026
Summary
CVE-2026-54133 is a critical-severity Improper Input Validation (CWE-20) vulnerability in Jmespath Jmespath. Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 23.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-36431
Vulnerability details
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…
more
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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
RCE via unsanitized JMESPath expressions in PHP apps directly enables exploitation of public-facing applications (T1190).
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Directly implements checks on information inputs to reject invalid data before processing.
Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.
Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.
Makes persistent code injection into loaded programs impossible when the executable image itself resides on hardware-protected read-only media.
Dynamically generated code can be produced and executed inside the isolated chamber, preventing host compromise from code-injection payloads.
Validating that output matches expected content directly mitigates failures to properly encode or escape data for its destination context.
Directly prevents execution of attacker-supplied code written into data memory regions.
Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.