TI-2025-21651 Aliases CVE-2025-30345 GHSA-fw4x-j9wf-qmp2

Improper output encoding in Intevation OpenSlides

MEDIUM 52CWE-116Published 2025-03-21 · Updated 2025-03-21

Key facts

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

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

Summary

An issue was discovered in OpenSlides before 4.2.5. When creating new chats via the chat_group.create action, the user is able to specify the name of the chat. Some HTML elements such as SCRIPT are filtered, whereas others are not. In most cases, HTML entities are encoded properly, but not when deleting chats or deleting messages in these chats. This potentially allows attackers to interfere with the layout of the rendered website, but it is unlikely that victims would click on deleted chats or deleted messages.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00288 21st percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix Fixed OpenSlides (Intevation): 4.2.5

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
Intevation	OpenSlides	before 4.2.5	4.2.5	Patch available	CNA

OpenSlides VendorIntevation Affected before 4.2.5 Fixed in 4.2.5 Patch available CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:openslides:openslides::::::::	before 4.2.5	Vulnerable	Intevation

cpe:2.3:a:openslides:openslides:*:*:*:*:*:*:*:* Versions before 4.2.5 Vulnerable ·Intevation

Remediation

Fix · CNA OpenSlides (Intevation) Fixed in 4.2.5

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

Release · 2025-03-21
Intevation OpenSlides 4.2.5
4 records Highest priority Priority MEDIUM 4 MEDIUM
Other records, highest priority first
- TI-2025-21650 Observable discrepancy in Intevation OpenSlidesPriority MEDIUM 63
- TI-2025-21649 Path traversal in Intevation OpenSlidesPriority MEDIUM 62
- TI-2025-21648 Cross-site scripting in Intevation OpenSlidesPriority MEDIUM 60
Show all 4 records →

Timeline

2026-10-02 Threatist record created from CVE-2025-30345
2026-10-03 Alias added: GHSA-fw4x-j9wf-qmp2

References

Exploit 1

https://www.x41-dsec.de/lab/advisories/x41-2025-001-OpenSlides

TI-2025-21650 Observable discrepancy in Intevation OpenSlides CVSS 3.1MEDIUM 5.3
TI-2025-21649 Path traversal in Intevation OpenSlides CVSS 3.1MEDIUM 6.5
TI-2025-21648 Cross-site scripting in Intevation OpenSlides CVSS 3.1MEDIUM 6.1
TI-2026-20628 OpenSlides has incorrect access control vulnerability in authentication service CVSS 3.1CRITICAL 9.8
TI-2020-16101 XSS in OpenSlides CVSS 3.1HIGH 8.9
TI-2024-15167 OpenSlides 4.0.15 verifies passwords by comparing password hashes using a function with… CVSS 3.1HIGH 7.5

See all 7 →

Sources

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