How severe is CVE-2025-66481?

CVE-2025-66481 has a CVSS 3.x base score of 9.6, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-66481 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-66481?

CVE-2025-66481 affects Thinkinai Deepchat. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-66481?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2025-66481 have an EU (EUVD) identifier?

Yes. CVE-2025-66481 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-201843.

When was CVE-2025-66481 published?

CVE-2025-66481 was published on 2025-12-09 and last updated on 2026-06-17.

CVE-2025-66481

CVE-2025-66481 is a critical-severity vulnerability in Thinkinai Deepchat with a CVSS 3.x base score of 9.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Critical (CVSS 3.x base score 9.6)
EPSS exploit prediction: 0% (39th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-201843
Weakness: CWE-79
Affected product: Thinkinai Deepchat
Published: 2025-12-09
Last modified: 2026-06-17

Description

DeepChat is an open-source AI chat platform that supports cloud models and LLMs. Versions 0.5.1 and below are vulnerable to XSS attacks through improperly sanitized Mermaid content. The recent security patch for MermaidArtifact.vue is insufficient and can be bypassed using unquoted HTML attributes combined with HTML entity encoding. Remote Code Execution is possible on the victim's machine via the electron.ipcRenderer interface, bypassing the regex filter intended to strip dangerous attributes. There is no fix at time of publication.

Frequently asked questions

What is CVE-2025-66481?: DeepChat is an open-source AI chat platform that supports cloud models and LLMs. Versions 0.5.1 and below are vulnerable to XSS attacks through improperly sanitized Mermaid content. The recent security patch for MermaidArtifact.vue is insufficient and can be bypassed using unquoted HTML attributes combined with HTML entity encoding. Remote Code Execution is possible on the victim's machine via the electron.ipcRenderer interface, bypassing the regex filter intended to strip dangerous attributes. There is no fix at time of publication.
How severe is CVE-2025-66481?: CVE-2025-66481 has a CVSS 3.x base score of 9.6, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-66481 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-66481?: CVE-2025-66481 affects Thinkinai Deepchat. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-66481?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2025-66481 have an EU (EUVD) identifier?: Yes. CVE-2025-66481 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-201843.
When was CVE-2025-66481 published?: CVE-2025-66481 was published on 2025-12-09 and last updated on 2026-06-17.

References

https://github.com/ThinkInAIXYZ/deepchat/security/advisories/GHSA-h9f5-7hhf-fqm4

Affected products (1)

cpe:2.3:a:thinkinai:deepchat:*:*:*:*:*:*:*:*

More vulnerabilities in Thinkinai Deepchat

CVE-2025-67744 — Critical (CVSS 9.6): DeepChat is an open-source artificial intelligence agent platform that unifies models, tools, and agents. Prior to…
CVE-2025-66222 — Critical (CVSS 9.6): DeepChat is a smart assistant uses artificial intelligence. In 0.5.0 and earlier, there is a Stored Cross-Site…
CVE-2025-58768 — Critical (CVSS 9.6): DeepChat is a smart assistant uses artificial intelligence. Prior to version 0.3.5, in the Mermaid chart rendering…
CVE-2025-55733 — Critical (CVSS 9.6): DeepChat is a smart assistant that connects powerful AI to your personal world. DeepChat before 0.3.1 has a one-click…

All CVEs affecting Thinkinai Deepchat →

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

CVE-2025-49410 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Imran Emu TC…
CVE-2024-47875 — Critical (CVSS 10.0): DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMpurify was vulnerable to…
CVE-2024-6886 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Gitea…
CVE-2023-45144 — Critical (CVSS 10.0): com.xwiki.identity-oauth:identity-oauth-ui is a package to aid in building identity and service providers based on…
CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
CVE-2022-4361 — Critical (CVSS 10.0): Keycloak, an open-source identity and access management solution, has a cross-site scripting (XSS) vulnerability in the…

Browse all CWE-79 (Cross-site Scripting (XSS)) vulnerabilities →