CVE-2026-40229Public exploitNetwork attack vector

Stored script execution via trusted author name

Published Apr 29, 2026 · Updated Apr 29, 2026

Stored XSS in Helpy 2.8.0 allows remote authenticated users to execute script in other users' browsers through a crafted account name. PostsHelper#post_message interpolates the stored name into a translation and calls html_safe without sanitizing or escaping the result. Registration or profile access is required to plant the payload, and execution occurs when a victim views a public thread or admin ticket, or opens an HTML notification email.

CVSS severity5.1
Medium
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

Stored XSS in Helpy 2.8.0 allows remote authenticated users to execute script in other users' browsers through a crafted account name. PostsHelper#post_message interpolates the stored name into a translation and calls html_safe without sanitizing or escaping the result. Registration or profile access is required to plant the payload, and execution occurs when a victim views a public thread or admin ticket, or opens an HTML notification email.

The record

CVE
CVE-2026-40229
Published
Apr 29, 2026
Updated
Apr 29, 2026
Vendor
Helpy
Product
Helpy
Classifications
CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 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=2.8.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Helpy · Helpyversion=2.8.0

Published CVSS scores

5.1Fluid AttacksCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

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

Public exploit references

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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