Medium Cross-site scripting

CVE-2026-56126 — pfSense Plus < 26.07 / CE < 2.9.0 Stored XSS via status_monitoring.php

pfSense Plus before 26.07 and CE before 2.9.0 allow authenticated users with the Status: Monitoring privilege to inject arbitrary JavaScript via graph configuration parameters in /status_monitoring.php. Multiple POST parameters including graph-left, graph-right, time-period, resolution, start-date, end-date, start-time, end-time, graph-type, invert, and refresh-interval are concatenated and written to the global pfSense XML configuration without sanitization, then echoed unsanitized into a JavaScript string context on page render. Because the setting is stored in the global configuration, the payload executes in the browser of every user who visits the Status: Monitoring page.

Published Sep 3, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: VulnCheck

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 1.1% (30-day exploitation probability)+10
Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

1.05%

ahead of 64% of scored CVEs · Oct 15, 2026

Affects

Netgate

Pfsense Ce and 1 more

CVSS base

5.4

Medium · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Netgate Pfsense Ce, Netgate Pfsense Plus).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Exploitation requires user interaction: tighten email/web filtering and warn affected users.
Search available logs for exploit probes matching the vulnerability class (cross-site scripting), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Netgate	Pfsense Ce	< 2.9.0	Vulnerable	CVE Program (cve.org) e CISA ADP
Netgate	Pfsense Plus	< 26.07	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

Low

User interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
5.1	CVSS 4.0	Medium	—	—	disclosure@vulncheck.com via NIST National Vulnerability Database
5.1	CVSS 4.0	Medium	—	—	VulnCheck via CVE Program (cve.org) e CISA ADP
5.4	CVSS 3.1	Medium	2.3	2.7	disclosure@vulncheck.com via NIST National Vulnerability Database
5.4	CVSS 3.1	Medium	—	—	VulnCheck via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N (score shown at the top: disclosure@vulncheck.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-79 · Cross-site Scripting (XSS)

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Monitor CSP violation reports and script payloads in reflected parameters.

web/proxy/WAF logsnetwork IDS/IPSapplication logs

Timeline

What happened to this CVE, newest first.

2026
Affected products added · netgate/pfsense plus, netgate/pfsense ce
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 15, 2026
CVSS changed · 5.4
Oct 15, 2026 · NIST National Vulnerability Database
Source status changed · → Awaiting Analysis
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Sep 3, 2026 · VulnCheck

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

4 on the record

docs.netgate.com/downloads/pfSense-SA-26_09.packages.asc
vendor-advisory, patch, NIST National Vulnerability Database
www.vulncheck.com/advisories/pfsense-plus-ce-stored-xss-via-status-monitoring-php
third-party-advisory, NIST National Vulnerability Database
docs.netgate.com/pfsense/en/latest/releases/2-9-0.html
release-notes, NIST National Vulnerability Database
docs.netgate.com/pfsense/en/latest/releases/26-07.html
release-notes, NIST National Vulnerability Database

Elsewhere on this site

Netgate
every CVE for this vendor

Cross-site scripting
same class

CWE-79
other pages naming this weakness

Related CVEs (same products)

Medium CVE-2026-111233 Netgate pfSense CE 2.7.1 through 2.9.0 Reflected XSS via firewall_rules.php 1d
High CVE-2026-111231 Netgate pfSense CE through 2.9.0 Authorization Bypass via config_restore() and config_install() 1d
Medium CVE-2026-111232 Netgate pfSense CE 2.3.0 through 2.9.0 Stored XSS via Separator Color 1d
Medium CVE-2026-111227 Netgate pfSense CE through 2.9.0 CRLF Injection via services_unbound_acls.php 1d
High CVE-2026-111226 Netgate pfSense CE 2.4.5 through 2.9.0 OS Command Injection via system_advanced_admin.php 1d
Medium CVE-2026-111230 Netgate pfSense CE through 2.9.0 Local File Read via Dynamic DNS Update URL 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-56126 is "pfSense Plus < 26.07 / CE < 2.9.0 Stored XSS via status_monitoring.php", rated Medium. It affects Pfsense Ce (Netgate); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.4 describes technical severity. EPSS 1.05% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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