Low Cross-site scripting exploit reference

CVE-2026-7015 — MaxSite CMS Guestbook Plugin cross site scripting

A vulnerability has been found in MaxSite CMS up to 109.3. This issue affects some unknown processing of the component Guestbook Plugin. Such manipulation of the argument f_text/f_slug/f_limit/f_email leads to cross site scripting. The attack may be launched remotely. The exploit has been disclosed to the public and may be used. Upgrading to version 109.4 is capable of addressing this issue. The name of the patch is 8a3946bd0a54bfb72a4d57179fcd253f2c550cd7. It is suggested to upgrade the affected component. The vendor was informed early about this issue. They classify it as a "Self-XSS". They deployed a countermeasure: "Nevertheless, we consider this a violation of secure coding standards. The lack of filtering via `htmlspecialchars()` has already been fixed in the latest patch to prevent incorrect data display."

Published Apr 26, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: VulDB

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 0.4% (30-day exploitation probability)+4
CISA SSVC: exploitation "poc"+5

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

0.38%

ahead of 30% of scored CVEs · Oct 14, 2026

Affects

MaxSite

CMS

CVSS base

2.4

Low · 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

Proof of concept

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 (MaxSite CMS).
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
MaxSite	CMS	version 109.0version 109.1version 109.2version 109.3	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

High

User interaction

Required

Scope

Unchanged

Confidentiality

None

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
4.8	CVSS 4.0	Medium	—	—	VulDB via CVE Program (cve.org) e CISA ADP
1.9	CVSS 4.0	Low	—	—	cna@vuldb.com via NIST National Vulnerability Database
2.4	CVSS 3.1	Low	0.9	1.4	cna@vuldb.com via NIST National Vulnerability Database
2.4	CVSS 3.1	Low	—	—	VulDB via CVE Program (cve.org) e CISA ADP
2.4	CVSS 3.0	Low	—	—	VulDB via CVE Program (cve.org) e CISA ADP
3.3	CVSS 2.0	Low	6.4	2.9	cna@vuldb.com via NIST National Vulnerability Database
3.3	CVSS 2.0	Low	—	—	VulDB via CVE Program (cve.org) e CISA ADP

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

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-79 · Cross-site Scripting (XSS)

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.38%

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 · maxsite/cms
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
CVSS changed · 2.4
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Deferred
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Apr 26, 2026 · VulDB

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

7 on the record

github.com/maxsite/cms/commit/8a3946bd0a54bfb72a4d57179fcd253f2c550cd7
patch, NIST National Vulnerability Database
github.com/maxsite/cms/releases/tag/v109
patch, NIST National Vulnerability Database
vuldb.com/vuln/359595/cti
signature, permissions-required, NIST National Vulnerability Database
github.com/wnaspy/CVE/blob/main/Report-%20Stored%20XSS-in-guestbook-plugin-maxsi
exploit, NIST National Vulnerability Database
vuldb.com/submit/796740
third-party-advisory, NIST National Vulnerability Database
vuldb.com/vuln/359595
vdb-entry, technical-description, NIST National Vulnerability Database
github.com/maxsite/cms/
product, NIST National Vulnerability Database

Elsewhere on this site

MaxSite
every CVE for this vendor

Cross-site scripting
same class

CWE-79
other pages naming this weakness

Related CVEs (same products)

Low CVE-2026-7016 MaxSite CMS ushki Plugin cross site scripting Apr 26, 2026
Low CVE-2026-7013 MaxSite CMS mail_send Plugin cross site scripting Apr 26, 2026
Low CVE-2026-7014 MaxSite CMS down_count Plugin cross site scripting Apr 26, 2026
Low CVE-2026-7012 MaxSite CMS Redirect Plugin cross site scripting Apr 25, 2026
Low CVE-2026-7011 MaxSite CMS Antispam Plugin plugin_antispam cross site scripting Apr 25, 2026
Critical CVE-2026-3395 MaxSite CMS MarkItUp Preview AJAX Endpoint preview-ajax.php eval code injection Mar 1, 2026

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-2026-7015 is "MaxSite CMS Guestbook Plugin cross site scripting", rated Low. It affects CMS (MaxSite); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 2.4 describes technical severity. EPSS 0.38% 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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