CVE-2026-66673Network attack vector

Browser script execution via reflected input

Published Aug 20, 2026 · Updated Aug 20, 2026

Cross-site scripting in Monkeysan Flatastic 2.0 and earlier allows remote attackers to execute script in victims' browsers via crafted input. Public records identify the issue only as reflected XSS; they do not disclose the affected endpoint, parameter, or output sink that reflects untrusted input into page content without neutralization. No authentication is required, but exploitation requires victim interaction such as loading a crafted request or page in the site's origin, and published scoring bounds impact to low confidentiality, integrity, and availability changes.

CVSS severity7.1
High
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Monkeysan Flatastic 2.0 and earlier allows remote attackers to execute script in victims' browsers via crafted input. Public records identify the issue only as reflected XSS; they do not disclose the affected endpoint, parameter, or output sink that reflects untrusted input into page content without neutralization. No authentication is required, but exploitation requires victim interaction such as loading a crafted request or page in the site's origin, and published scoring bounds impact to low confidentiality, integrity, and availability changes.

The record

CVE
CVE-2026-66673
Published
Aug 20, 2026
Updated
Aug 20, 2026
Vendor
Monkeysan
Product
Flatastic
Classifications
CWE-79, CAPEC-591
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=n/a <=2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Monkeysan · Flatasticversion=n/a <=2.0

Published CVSS scores

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

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

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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