CVE-2025-5455

Possible denial of service when passing malformed data in a URL to qDecodeDataUrl

Published Jun 2, 2025 CVSS 4.0 · 8.4 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2025-16625 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.
History
Type Values Removed Values Added
Description 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. 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.
First Time appeared Qt
Qt qt
CPEs cpe:2.3:a:qt:qt:*:*:*:*:*:*:*:*
cpe:2.3:a:qt:qt:6.5.9:*:*:*:*:*:*:*
cpe:2.3:a:qt:qt:6.8.4:*:*:*:*:*:*:*
cpe:2.3:a:qt:qt:6.9.0:*:*:*:*:*:*:*
cpe:2.3:a:qt:qt:6.9.1:*:*:*:*:*:*:*
Vendors & Products Qt
Qt qt
Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:enterprise_linux:10.0
Vendors & Products Redhat
Redhat enterprise Linux
Type Values Removed Values Added
Weaknesses CWE-617
Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

threat_severity

Moderate

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title Possible denial of service when passing malformed data in a URL to qDecodeDataUrl
Weaknesses CWE-20
References
Metrics cvssV4_0

{'score': 8.4, '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
TQtC
Published
Updated
Jul 29, 2026, 7:34 AM
Reserved
Jun 2, 2025, 8:31 AM
Status
Deferred
Published
Jun 2, 2025, 9:15 AM
Modified
Jul 29, 2026, 9:16 AM
Severity
Moderate
Public date
Jun 2, 2025, 8:46 AM