CVE-2025-5455 HIGH

CVE-2025-5455: Possible denial of service when passing malformed data in a URL to qDecodeDataUrl

Vendor The Qt Company
Product Qt
Weakness CWE-20 · Input validation
Published June 2, 2025
Last update June 2, 2025

CVSS base score

8.4/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H/R:U/RE:M/U:Clear

What the vulnerability does

01Description

An issue was found in the private API function qDecodeDataUrl() in QtCore, which is used in QTextDocument and QNetworkReply, and, potentially, in user code. If the function was called with malformed data, for example, an URL that contained a "charset" parameter that lacked a value (such as "data:charset,"), and Qt was built with assertions enabled, then it would hit an assertion, resulting in a denial of service (abort). This impacts Qt up to 5.15.18, 6.0.0->6.5.8, 6.6.0->6.8.3 and 6.9.0. This has been fixed in 5.15.19, 6.5.9, 6.8.4 and 6.9.1.

Key dates

02Disclosure timeline

June 2, 2025 CVE published
June 2, 2025 Record updated