CVE-2023-49170Network attack vector

Unauthenticated browser script execution

Published Dec 15, 2023 · Updated Apr 28, 2026

Reflected XSS in 123FormBuilder Forms by CaptainForm 2.5.3 and earlier allows remote attackers to execute script in a user's browser. The CNA and its sole referenced advisory do not identify the affected request parameter, rendering sink, or missing output-encoding operation. Exploitation requires a user to interact with attacker-controlled content; no server-side code execution is reported.

CVSS severity7.1
High
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in 123FormBuilder Forms by CaptainForm 2.5.3 and earlier allows remote attackers to execute script in a user's browser. The CNA and its sole referenced advisory do not identify the affected request parameter, rendering sink, or missing output-encoding operation. Exploitation requires a user to interact with attacker-controlled content; no server-side code execution is reported.

The record

CVE
CVE-2023-49170
Published
Dec 15, 2023
Updated
Apr 28, 2026
Vendor
123FormBuilder
Product
Forms by CaptainForm – Form Builder for WordPress
Classifications
CWE-79, CAPEC-591, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 15, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=n/a <=2.5.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

123FormBuilder · Forms by CaptainForm – Form Builder for WordPressversion=n/a <=2.5.3

Published CVSS scores

7.1PatchstackCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L
6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CAPEC-591Reflected XSS
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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