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NVD / CVE Program· CNA VulnCheck

CVE-2023-7312: Nagios Fusion < 4.2.0 Email Settings Stored XSS via SMTP/sendmail

Noroxi assessment

Priority: Monitor (action score 24/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 1% (FIRST EPSS); higher than 62.7% of all records.
  • Anyone who can reach it over the internet can trigger it. Administrator privileges are required. No special conditions are required; it is repeatable.
  • Fixed version: Nagios Fusion 4.2.0.

Low priority for now. Upgrade to Nagios Fusion 4.2.0 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Nagios Fusion versions prior to 4.2.0 contain a stored cross-site scripting (XSS) vulnerability when adding or configuring Email Settings. Unsanitized user input can be stored and later rendered in the administrative UI, causing JavaScript to execute in the browser of any user who views the affected page. An attacker who can add or modify SMTP/email settings or manipulate the sendmail configuration fields could persist a malicious payload that executes in the context of other users' browsers.

MediumCVSS 6.2 · v4.0—No exploit Fix available
Published
Oct 30, 2025
Updated
Oct 18, 2026
EPSS
1.0% · 62th percentile

Report tools

JSON

Action score

24

Monitor

Low priority for now.

CVSS
24 / 40 · 6.2 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 1.0%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · VulnCheck
6.2
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2023-7312

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
nagiosfusion

Limit the impact of XSS

This is a cross-site scripting (XSS) vulnerability. A well-configured Content-Security-Policy doesn't fix it, but greatly reduces its impact. Check your site's CSP and other security headers for free.

Check security headers

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • nagios fusionbefore 4.2.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (VulnCheck). Independent of NVD's CPE analysis and usually ahead of it.

  • Nagios Fusion

    • before 4.2.0affected · semver

Same product

nagios: all records

Other highest-scoring records for the same primary product.

  • CVE-2020-28905Improper Input Validation in Nagios Fusion 4.1.8 and earlier allows an authenticated attacker to execute remote code via table pagination.
    43Plan
  • CVE-2020-28901Command Injection in Nagios Fusion 4.1.8 and earlier allows for Privilege Escalation or Code Execution as root via vectors related to corrup
    43Plan
  • CVE-2020-28902Command Injection in Nagios Fusion 4.1.8 and earlier allows Privilege Escalation from apache to root in cmd_subsys.php.
    42Plan

Published before and after this one in the same product

  • ← EarlierCVE-2018-25119Oct 30, 2025 · Nagios Fusion < 4.1.5 XSS via fusionwindow Parameter
    20Monitor
  • ← EarlierCVE-2023-53689Oct 30, 2025 · Nagios Fusion < 4.2.0 License Information Reflected XSS
    24Monitor
  • ← EarlierCVE-2023-53690Oct 30, 2025 · Nagios Fusion < 4.2.0 LDAP/AD Integration Stored XSS
    24Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Nagios Fusion4.2.0Vendor (CNA)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2023-536890 days apartNagios Fusion < 4.2.0 License Information Reflected XSS
    24Monitor
  • CVE-2023-536900 days apartNagios Fusion < 4.2.0 LDAP/AD Integration Stored XSS
    24Monitor
  • CVE-2017-202090 days apartNagios Fusion < 4.0.1 XSS via Users/Servers Page
    20Monitor
  • CVE-2018-251190 days apartNagios Fusion < 4.1.5 XSS via fusionwindow Parameter
    20Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • Administrator privileges are required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
High
User interaction
P
Scope
X

Weakness class (CWE)

CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/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

nvd-secondary

Root cause

User content is inserted into the page as HTML. The browser interprets the content as code rather than data.

The bug in code

The whole CWE-79 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

ts
commentEl.innerHTML = comment.body;

Fixed

ts
commentEl.textContent = comment.body;

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records