MISP: PHP phar stream wrapper enables deserialization and code execution via caller-influenced filesystem paths

published 2026-09-22 48 d ago modified 2026-09-22 47 d ago also EUVD-2026-84466

cvss: 7.7; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 33%
public exploits: 0; none known

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.

Patch / fix

fixed in 1 links 1

MISP MISP 2.5.47

github.com/MISP/MISP@08fa755 commit

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 48 d ago (2026-09-22)

Exploit prediction

0.39% chance of exploitation in the next 30 days, higher than 33% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	7.7	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
CNA	4.0	7.7	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

Affected products

MISP MISP

Classification

Weakness

CWE-502 Deserialization of Untrusted Data
CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component

References

github.com /MISP/MISP/commit/08fa755b6
patch

Sources

CVE List CVE-2026-95806
NVD CVE-2026-95806

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary