Cyber Resilience

CVE-2026-56700

CriticalPublic PoCRCE

Published: 30 June 2026

Published
30 June 2026
Modified
01 July 2026
KEV Added
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Patch
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CVSS Score v4 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0168 74.2th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-56700 is a critical-severity OS Command Injection (CWE-78) vulnerability. Its CVSS base score is 9.3 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 25.8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and AC-6 (Least Privilege).

OWASP Top 10 for Web (2025)

A05:2025 InjectionA08:2025 Software or Data Integrity Failures

EU & UK References

Vulnerability details

Grav CMS before 2.0.0-beta.2 contains multiple code-execution vulnerabilities. Three unsafe unserialize() calls - in Scheduler\JobQueue, Framework\Cache\Adapter\FileCache, and Session - deserialize untrusted data without restricting allowed classes, enabling PHP object injection and, via a gadget chain, arbitrary code execution where an…

more

attacker controls the serialized input. Additionally, InstallCommand's git clone operation passes the branch, url, and path parameters into a shell command without escaping, allowing OS command injection via plugin/theme installation (which requires admin access). A Twig security blocklist bypass (server-side template injection) is also present. The issues are fixed in 2.0.0-beta.2.

CWE(s)
CWE-78CWE-502

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
attack.mitre.org →
Why these techniques?

Public-facing CMS RCE via deserialization + OS command injection directly enables T1190 and T1059.004.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-30861Shared CWE-78
CVE-2024-57016Shared CWE-78
CVE-2026-27728Shared CWE-78
CVE-2025-8613Shared CWE-78
CVE-2026-27626Shared CWE-78
CVE-2025-2257Shared CWE-78
CVE-2026-33208Shared CWE-78
CVE-2026-32892Shared CWE-78
CVE-2026-2043Shared CWE-78
CVE-2013-10048Shared CWE-78

Affected Assets

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match
prevent

Directly requires validation of untrusted inputs to block unsafe unserialize() calls, unescaped shell parameters, and template injection vectors.

AC-6 Least Privilege partial match
prevent

Enforces least privilege so that only minimal accounts can reach the admin-only InstallCommand path that enables OS command injection.

SI-7 Software, Firmware, and Information Integrity partial match
preventdetect

Requires integrity verification of software and serialized objects to detect or block gadget-chain execution resulting from PHP object injection.

References