CVE-2026-66490Network attack vector

Browser script execution via stored comment avatar

Published Jul 29, 2026 · Updated Jul 29, 2026

Stored cross-site scripting in Balbooa Gridbox 1.0.0 through 2.20.1 allows remote attackers to execute script via a comment avatar. The stored avatar is the injection locus, but the reporter withholds the endpoint, parameter, and code path that fail to neutralize it. No account is required, but a visitor must load the affected comment; script then runs in that visitor's browser and can read or alter page data.

CVSS severity6.1
Medium
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored cross-site scripting in Balbooa Gridbox 1.0.0 through 2.20.1 allows remote attackers to execute script via a comment avatar. The stored avatar is the injection locus, but the reporter withholds the endpoint, parameter, and code path that fail to neutralize it. No account is required, but a visitor must load the affected comment; script then runs in that visitor's browser and can read or alter page data.

The record

CVE
CVE-2026-66490
Published
Jul 29, 2026
Updated
Jul 29, 2026
Vendor
Balbooa
Product
Gridbox
Classifications
CWE-79, CAPEC-18, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 29, 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=1.0.0-2.20.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Balbooa · Gridboxversion=1.0.0-2.20.1

Published CVSS scores

6.1CISA-ADPCVSS: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-18XSS Targeting Non-Script Elements
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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