CVE-2026-9499 Affecting qt6-qt5compat package, versions <0:6.10.1-1.el10_2.1


Severity

Recommended
high

Based on AlmaLinux security rating.

Threat Intelligence

EPSS
0.3% (23rd percentile)

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  • Snyk IDSNYK-ALMALINUX10-QT6QT5COMPAT-19675767
  • published11 Sept 2026
  • disclosed9 Sept 2026

Introduced: 9 Sep 2026

CVE-2026-9499  (opens in a new tab)

How to fix?

Upgrade AlmaLinux:10 qt6-qt5compat to version 0:6.10.1-1.el10_2.1 or higher.
This issue was patched in ALSA-2026:65816.

NVD Description

Note: Versions mentioned in the description apply only to the upstream qt6-qt5compat package and not the qt6-qt5compat package as distributed by AlmaLinux. See How to fix? for AlmaLinux:10 relevant fixed versions and status.

An out-of-bounds read (buffer over-read) vulnerability exists in QTextCodec::codecForName() in Qt. When the function is called with a QByteArray that is not NUL-terminated (for example, one created with QByteArray::fromRawData()), the codec-name matching routine reads past the end of the supplied buffer. In most cases this results in an incorrect text codec being selected; in the worst case, if the over-read reaches unmapped memory, the process crashes (denial of service). The over-read is bounded by the length of the longest codec-name candidate, and the out-of-bounds bytes are only compared internally against Qt's fixed list of codec names, so no data is disclosed to an attacker. Applications that do not pass non-NUL-terminated QByteArrays to QTextCodec::codecForName() are not exposed. The affected code resides in the Qt5Compat module from Qt 6.0.0 onward, and in Qt Core (qtbase) in Qt 4.x and Qt 5.x.

CVSS Base Scores

version 3.1