CVE Intelligence
Medium Injection

CVE-2026-101335 — Forminator Forms <= 1.58.1 - Unauthenticated Arbitrary Shortcode Execution via 'User-Agent' Header and 'referer_url' Parameter via Quiz Notification Merge Tags

The Forminator Forms – Contact Form, Payment Form & Custom Form Builder plugin for WordPress is vulnerable to Arbitrary Shortcode Execution in versions up to, and including, 1.58.1. This is due to the forminator_replace_quiz_form_data() helper invoking do_shortcode() on the fully expanded notification body once the {quiz_result} merge tag has been substituted, while the earlier-substituted {user_agent} and {refer_url} merge tags carry unauthenticated attacker-controlled bytes (the User-Agent header and the referer_url POST parameter) through sanitize_text_field()/esc_html(), neither of which strip the '[' and ']' shortcode delimiters. This makes it possible for unauthenticated attackers to execute arbitrary WordPress shortcodes registered on the site by submitting a quiz whose notification template contains {quiz_result}; the resulting impact depends on the shortcodes exposed by other installed plugins/themes and can range from arbitrary content injection to information disclosure.

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

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
  • Automatable exploitation (SSVC)+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
—
No EPSS score.
Affects
Wpmudev
Forminator Forms – Contact Form, Payment Form & Custom Form Builder
CVSS base
6.5
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
Yes
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 (Wpmudev Forminator Forms – Contact Form, Payment Form & Custom Form Builder).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  4. Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Wpmudev Forminator Forms – Contact Form, Payment Form & Custom Form Builder ≤ 1.58.1 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
None
User interaction
None
Scope
Unchanged
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
6.5 CVSS 3.1 Medium 3.9 2.5 security@wordfence.com via NIST National Vulnerability Database
6.5 CVSS 3.1 Medium — — Wordfence via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N (score shown at the top: security@wordfence.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-94 · Code Injection

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).
  • Look for parameters with command/query metacharacters and unexpected child processes of the service.
web/proxy/WAF logsnetwork IDS/IPSapplication logsendpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

  • 2026
  • SSVC assessment updated
    Oct 16, 2026 · CVE Program (cve.org) e CISA ADP
  • Source status changed · Received → Deferred
    Oct 16, 2026 · NIST National Vulnerability Database
  • Source status changed · Published → Received
    Oct 16, 2026 · NIST National Vulnerability Database
  • Record published
    Oct 16, 2026
  • CVSS changed · 6.5
    Oct 16, 2026 · CVE Program (cve.org) e CISA ADP
  • Source status changed · → Published
    Oct 16, 2026 · CVE Program (cve.org) e CISA ADP
  • Record created in this database
    Oct 16, 2026 · CVE Program (cve.org) e CISA ADP
  • CVE published
    Oct 16, 2026 · Wordfence

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 16, 2026 – Oct 16, 2026

References

7 on the record

Elsewhere on this site

Wpmudev
every CVE for this vendor
Injection
same class
CWE-94
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-103911 Forminator Forms <= 1.58.1 - Unauthenticated Arbitrary Shortcode Execution via 's' Search Parameter and Anonymous Comment via render_block 12h
  • CVE-2026-92144 Forminator Forms <= 1.57.2 - Unauthenticated Stored Cross-Site Scripting via 'postdata-1[post-custom]' Parameter 15d
  • CVE-2026-85235 Forminator Forms <= 1.57.2 - Unauthenticated Stored Cross-Site Scripting via Rich-Text Textarea Field 15d
  • CVE-2026-92229 Forminator Forms <= 1.57.2 - Unauthenticated Arbitrary Shortcode Execution via 'current_url' Parameter 27d
  • CVE-2026-18324 Forminator Forms <= 1.57.0.1 - Unauthenticated Stored Cross-Site Scripting via Rich-Text Textarea Field Aug 28, 2026
  • CVE-2026-18323 Forminator Forms <= 1.57.0.2 - Unauthenticated Stored Cross-Site Scripting via Radio Field (Save and Continue Draft) Aug 25, 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 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-2026-101335 is "Forminator Forms <= 1.58.1 - Unauthenticated Arbitrary Shortcode Execution via 'User-Agent' Header and 'referer_url' Parameter via Quiz Notification Merge Tags", rated Medium. It affects Forminator Forms – Contact Form, Payment Form & Custom Form Builder (Wpmudev); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.5 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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