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.

The remote Oracle Linux 10 host has packages installed that are affected by a vulnerability as referenced in the ELSA-2025-9486 advisory.

    [6.8.1-9]
    - qt5: qt6: QtCore Assertion Failure Denial of Service (CVE-2025-5455)

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote AlmaLinux 9 host has packages installed that are affected by a vulnerability as referenced in the ALSA-2025:9462 advisory.

    * qt5: qt6: QtCore Assertion Failure Denial of Service (CVE-2025-5455)

Tenable has extracted the preceding description block directly from the AlmaLinux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Oracle Linux 9 host has packages installed that are affected by a vulnerability as referenced in the ELSA-2025-9462 advisory.

    [5.15.9-11]
    - qt5: QtCore Assertion Failure Denial of Service       Resolves: RHEL-96233

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 10 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2025:9486 advisory.

    Qt is a software toolkit for developing applications.  This package contains base tools, like string, xml,     and network handling.

    Security Fix(es):

    * qt5: qt6: QtCore Assertion Failure Denial of Service (CVE-2025-5455)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 9 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2025:9462 advisory.

    Qt is a software toolkit for developing applications. The qt5-base packages contain base tools for string,     xml, and network handling in Qt.

    Security Fix(es):

    * qt5: qt6: QtCore Assertion Failure Denial of Service (CVE-2025-5455)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Fedora 42 host has packages installed that are affected by multiple vulnerabilities as referenced in the FEDORA-2025-c546fd3f09 advisory.

    Qt 6.9.1 bugfix release.


Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
240973	Oracle Linux 10 : qt6-qtbase (ELSA-2025-9486)	Nessus	Oracle Linux Local Security Checks	high
240947	AlmaLinux 9 : qt5-qtbase (ALSA-2025:9462)	Nessus	Alma Linux Local Security Checks	high
240501	Oracle Linux 9 : qt5-qtbase (ELSA-2025-9462)	Nessus	Oracle Linux Local Security Checks	high
240479	RHEL 10 : qt6-qtbase (RHSA-2025:9486)	Nessus	Red Hat Local Security Checks	high
240475	RHEL 9 : qt5-qtbase (RHSA-2025:9462)	Nessus	Red Hat Local Security Checks	high
238286	Fedora 42 : LabPlot / dtk6core / dtk6gui / dtk6log / dtk6widget / fcitx5-qt / etc (2025-c546fd3f09)	Nessus	Fedora Local Security Checks	medium

Detections

Analytics

CVE-2025-5455

high

Tenable Plugins

high

high

high

high

high

medium