Helpy 2.8.0 - Stored XSS in knowledgebase Doc body rendering

published 2026-04-29 6 mo ago modified 2026-10-26 13 d ago also EUVD-2026-26245

cvss: 5.4; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 7%
public exploits: 0; none known

Helpy contains a stored cross-site scripting vulnerability in the knowledge base Doc rendering logic. An authenticated attacker with admin or agent editor privileges can persist arbitrary HTML or JavaScript in the body field of a knowledge base Doc.This issue affects helpy: 2.8.0.

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 6 mo ago (2026-04-29)

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

fluidattacks.com https://fluidattacks.com/es/advisories/prisioneros referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	4.8	CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
CNA	4.0	4.8	CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD	3.1	5.4	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Affected products

helpyio helpy

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

fluidattacks.com /es/advisories/prisioneros
third-party-advisory, exploit
github.com /helpyio/helpy
product

Sources

CVE List CVE-2026-40230
NVD CVE-2026-40230

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary