CVE-2026-95806: MISP: PHP phar stream wrapper enables deserialization and code execution via caller-influenced filesystem paths

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of 29 Oct 2026. If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?

0.4%

EPSS score, percentile 33.3 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

7.7 High

CVSS v4.0 base score, given by the CNA

What should I do?

The phar stream wrapper is unregistered via stream_wrapper_unregister('phar') at the top of both the web and console entry points … Full textSolution from the CVE record.

CISA has set no required action, because the vulnerability is not in KEV.

Advisories and patches (1)

Which versions are affected?

Affected

• before 2.5.47

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026; CVE List, as of 29 Oct 2026. About the data.

What to do

Solution (from the CVE record)

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.

Advisories and patches

• Security patch (Patch)

This summary is based on the CVE record as of 29 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

As listed in the CVE record.

Source: CVE List, as of 29 Oct 2026. About the data.

About this vulnerability

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 reloc…

Summary: CVE record, as of 29 Oct 2026.

• CISA has not added CVE-2026-95806 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
• The CVE record was published on 22 Sep 2026.
• The CVE record carries a CVSS v4.0 base score of 7.7 (High), given by its CNA.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.4% (percentile 33.3), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
• CISA's SSVC assessment in the CVE record: exploitation none, automatable no, technical impact total.
• The credits in the CVE record name Anthropic (Claude) as finder.

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; CVE List, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026. About the data.

Description

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

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.

Source: CVE List, as of 29 Oct 2026. About the data.

Timeline