MISP: PHP phar stream wrapper enables deserialization and code execution via caller-influenced filesystem paths
Summary
| CVE | CVE-2026-95806 |
|---|---|
| State | PUBLISHED |
| Assigner | CIRCL |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-22 16:18:24 UTC |
| Updated | 2026-09-22 16:18:24 UTC |
| Description | MISP ships with PHP's phar stream wrapper registered in both its web entry point and its console entry point. The phar stream wrapper causes PHP to treat a phar archive as a directory, which has two security consequences: - any filesystem operation on a caller-influenced path that resolves to a phar archive triggers an implicit unserialize() call, creating a deserialization sink; - a relocated application root can reach executable code inside an uploaded phar file, enabling arbitrary code execution as the web user. No component of MISP, the vendored CakePHP framework, or any runtime-loaded library reads or constructs phar archives. The wrapper therefore serves no legitimate purpose in the MISP runtime and exists solely as an available primitive for an attacker who can influence a filesystem path argument. |
Risk And Classification
Primary CVSS: v4.0 7.7 HIGH from 5a6e4751-2f3f-4070-9419-94fb35b644e8
CVSS:4.0/AV:N/AC:H/AT:N/PR:L/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
Problem Types: CWE-74 | CWE-502 | CWE-502 CWE-502 Deserialization of Untrusted Data | CWE-74 CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | 5a6e4751-2f3f-4070-9419-94fb35b644e8 | Secondary | 7.7 | HIGH | CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 7.7 | HIGH | CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
CVSS v4.0 Breakdown
CVSS:4.0/AV:N/AC:H/AT:N/PR:L/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
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/MISP/MISP/commit/08fa755b6 | 5a6e4751-2f3f-4070-9419-94fb35b644e8 | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: iglocska (en)
CNA: Claude Opus 5 (1M context) (en)
Additional Advisory Data
Solutions
CNA: The phar stream wrapper is unregistered via stream_wrapper_unregister('phar') at the top of both the web and console entry points, before any framework bootstrap or application code executes. Because no MISP component, CakePHP, or runtime library requires the phar wrapper, removing it eliminates the implicit unserialize() sink and the directory-like phar archive behavior without functional impact. This closes the deserialization and code-execution primitive application-wide, independent of whether individual callers validate their path arguments.