CVE Intelligence
Medium File handling exploit reference

CVE-2026-102366 — mall4j through 4.0 Unrestricted File Upload in Admin File Endpoints

mall4j through 4.0 contains an unrestricted file upload vulnerability in FileController endpoints that lack authorization checks and accept arbitrary file types without validation. Attackers with any authenticated token can upload HTML or SVG files that execute scripts in administrator browsers when accessed from the local storage path, resulting in stored cross-site scripting.

Published Sep 28, 2026 · Updated Oct 16, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: VulnCheck

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
  • Technical severity (medium)+3
  • 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
—
No EPSS score.
Affects
Gz-yami
Mall4j
CVSS base
4.4
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
Proof of concept
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 (Gz-yami Mall4j).
  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 (file handling), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Gz-yami Mall4j ≤ 4.0 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
High
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.

ScoreVersionSeverityExpl.ImpactScored by
2.1 CVSS 4.0 Low — — disclosure@vulncheck.com via NIST National Vulnerability Database
2.1 CVSS 4.0 Low — — VulnCheck via CVE Program (cve.org) e CISA ADP
4.4 CVSS 3.1 Medium 1.3 2.7 disclosure@vulncheck.com via NIST National Vulnerability Database
4.4 CVSS 3.1 Medium — — VulnCheck via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:H/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-434 · Unrestricted Upload of File with Dangerous Type

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 file creation in web directories and paths with traversal sequences (../).
web/proxy/WAF logsnetwork IDS/IPSfile integrity (FIM)endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · gz-yami/mall4j
    Oct 16, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 16, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 15, 2026
  • CVSS changed · 4.4
    Oct 15, 2026 · NIST National Vulnerability Database
  • Source status changed · → Deferred
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVE published
    Sep 28, 2026 · VulnCheck

Source activity

Repeated readings are counted rather than listed.

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

References

5 on the record

Elsewhere on this site

Gz-yami
every CVE for this vendor
File handling
same class
CWE-434
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-108691 mall4j through 4.0 Operator Precedence Error Deletes Other Users' Cart Items via /p/shopCart/cleanExpiryProdList 5d
  • CVE-2026-108690 mall4j through 4.0 Operator Precedence Error Exposes Other Users' Cart Items via /p/shopCart/expiryProdList 5d
  • CVE-2026-102367 mall4j through 4.0 Insufficient Session Expiration via Token Refresh 17d
  • CVE-2026-102361 mall4j through 4.0 Missing Authentication in Password Update Endpoint 17d
  • CVE-2026-102362 mall4j through 4.0 Missing Authentication in Product Review Deletion 17d
  • CVE-2026-102363 mall4j through 4.0 Unauthenticated Shipment Tracking Disclosure via Order Number 17d

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 FIRST EPSS score.
  • 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-2026-102366 is "mall4j through 4.0 Unrestricted File Upload in Admin File Endpoints", rated Medium. It affects Mall4j (Gz-yami); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 4.4 describes technical severity. 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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