CVE-2026-66457Network attack vector

Unauthenticated XSS via grouped event list rendering

Published Aug 6, 2026 · Updated Aug 6, 2026

Cross-site scripting in Marcus Sykes Events Manager 7.4.1 and earlier allows remote attackers to execute scripts through grouped event lists. The vendor identifies grouped event-list rendering as the affected locus, but public records do not disclose the function, input, output sink, or storage behavior. Exploitation requires no account but requires a visitor to load the affected list, allowing script execution in that visitor's browser.

CVSS severity7.1
High
EPSS probability0.19%
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 Marcus Sykes Events Manager 7.4.1 and earlier allows remote attackers to execute scripts through grouped event lists. The vendor identifies grouped event-list rendering as the affected locus, but public records do not disclose the function, input, output sink, or storage behavior. Exploitation requires no account but requires a visitor to load the affected list, allowing script execution in that visitor's browser.

The record

CVE
CVE-2026-66457
Published
Aug 6, 2026
Updated
Aug 6, 2026
Vendor
Marcus Sykes
Product
Events Manager
Classifications
CWE-79, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 6, 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 <=7.4.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Marcus Sykes · Events Managerversion=n/a <=7.4.1

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.

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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')
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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