TI-2026-30179 Aliases CVE-2026-41661 GHSA-gq27-fc8w-vcmp

Admidio: Reflected XSS in msg_window.php via Square Bracket to HTML Tag Conversion

MEDIUM 60CWE-79Published 2026-05-07 · Updated 2026-05-07

Key facts

Attack vector: Network
Privileges required: None
User interaction: Required
Attack complexity: Low
Impact type: Cross-site scripting
Confidentiality · integrity · availability: Low · Low · None
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-79.

Summary

Admidio is an open-source user management solution. Prior to version 5.0.9, an unauthenticated attacker can execute arbitrary JavaScript in any Admidio user's browser through a reflected XSS in system/msg_window.php. The endpoint passes user input through htmlspecialchars(), which does not encode square brackets. A subsequent call to Language::prepareTextPlaceholders() converts those brackets into HTML angle brackets, producing executable markup. This issue has been patched in version 5.0.9.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00181 7th percentileScored 2026-11-07

Fix Fixed admidio (Admidio): 5.0.9admidio/admidio (Packagist): 5.0.9

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Admidio	admidio	before 5.0.9	5.0.9	Patch available	CNA
—	admidio/admidio (Packagist)	before 5.0.9	5.0.9	Patch available	GHSA-gq27-fc8w-vcmp

admidio VendorAdmidio Affected before 5.0.9 Fixed in 5.0.9 Patch available CNA
admidio/admidio (Packagist) Vendor— Affected before 5.0.9 Fixed in 5.0.9 Patch available GHSA-gq27-fc8w-vcmp

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:a:admidio:admidio::::::::	—	—	Admidio

cpe:2.3:a:admidio:admidio:*:*:*:*:*:*:*:* Versions — — ·Admidio

Remediation

Fix · CNA admidio (Admidio) Fixed in 5.0.9
Fix · GHSA-gq27-fc8w-vcmp admidio/admidio (Packagist) Fixed in 5.0.9 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-41661
2026-10-03 Alias added: GHSA-gq27-fc8w-vcmp

References

Advisory 1

https://nvd.nist.gov/vuln/detail/CVE-2026-41661

Other 3

TI-2026-25286 Admidio is Missing Authorization and CSRF Protection on Document and Folder Deletion CVSS 3.1CRITICAL 9.1
TI-2026-56995 Admidio before 5.0.12 Authentication Bypass via RSS feeds CVSS 4.0HIGH 8.7
TI-2026-56993 Admidio before 5.0.12 SQL Injection via relation_type_list CVSS 4.0HIGH 8.7
TI-2024-25222 Admidio has Blind SQL Injection in ecard_send.php CVSS 3.1CRITICAL 10.0
TI-2026-30186 Admidio: SAML Signature Validation Result Ignored — Forged AuthnRequests and LogoutRequests Processed CVSS 3.1HIGH 8.2
TI-2024-25764 Admidio Vulnerable to RCE via Arbitrary File Upload in Message Attachment CVSS 3.1CRITICAL 9.1

See all 72 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences