CVE Intelligence
Low Cross-site scripting

CVE-2026-104807 — Mitel MiVoice Office 400 stored Cross-Site Scripting

DigitalCanion has discovered a stored Cross-Site Scripting (XSS) vulnerability that allows an authenticated malicious user to inject persistent JavaScript or HTML content into the web application. The specific flaw exists within the web portal listening on TCP port 443, under Configuration → Domains, specifically in the “Description” field. The application fails to properly validate or sanitize user-supplied input before storing and subsequently rendering the field. By injecting malicious JavaScript into the Description field, an attacker can modify the content and behavior of the affected page when it is viewed by other users. This could allow an attacker to alter the page's appearance, display attacker-controlled content, or construct convincing phishing scenarios within the application's trusted web context.

Published Oct 5, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: NCSC.ch

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 0.2% (30-day exploitation probability)+2

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
0.25%
ahead of 15% of scored CVEs · Oct 14, 2026
Affects
Mitel
Mitel MiVoice Office 400
CVSS base
1.9
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
None
none · proof-of-concept · active
Automatable
No
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.

  1. Identify exposed assets running the affected vendor/product/version combinations (Mitel Mitel MiVoice Office 400).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Exploitation requires user interaction: tighten email/web filtering and warn affected users.
  4. 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.

VendorProductVersionsStatusSource
Mitel Mitel MiVoice Office 400 version 11.0.96.0 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
Attack requirements
None
Privileges required
High
User interaction
Passive
Scope
X
Confidentiality (vulnerable system)
Low
Integrity (vulnerable system)
Low
Availability (vulnerable system)
None
Confidentiality (subsequent)
Low
Integrity (subsequent)
Low
Availability (subsequent)
None

Every base score collected

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

ScoreVersionSeverityExpl.ImpactScored by
1.9 CVSS 4.0 Low — — vulnerability@ncsc.ch via NIST National Vulnerability Database
1.9 CVSS 4.0 Low — — NCSC.ch via CVE Program (cve.org) e CISA ADP
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:P/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:Y/R:A/V:D/RE:L/U:Amber (score shown at the top: vulnerability@ncsc.ch)

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 0.25%

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 · mitel/mitel mivoice office 400
    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 · 1.9
    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
    Oct 5, 2026 · NCSC.ch

Source activity

Repeated readings are counted rather than listed.

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

References

1 on the record

Elsewhere on this site

Mitel
every CVE for this vendor
CWE-79
other pages naming this weakness

Related CVEs (same products)

  • High CVE-2026-104811 Mitel MiVoice Office 400 Music on Hold WAV File Upload Code Execution 10d
  • High CVE-2026-104809 Mitel MiVoice Office 400 Shared Object Hijacking Leading to Arbitrary Code Execution 10d
  • High CVE-2026-104810 Mitel MiVoice Office 400 File Management File Browser path traversal vulnerability 10d
  • Low CVE-2026-104808 Mitel MiVoice Office 400 stored Cross-Site Scripting 10d
  • High CVE-2026-104805 Mitel MiVoice Office 400 Backup Restoration Arbitrary File Write Leading to Root Code Execution 10d
  • High CVE-2026-104706 Mitel MiVoice Office 400 view system files path traversal 10d

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-2026-104807 is "Mitel MiVoice Office 400 stored Cross-Site Scripting", rated Low. It affects Mitel MiVoice Office 400 (Mitel); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 1.9 describes technical severity. EPSS 0.25% 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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