# CVE-2026-9499: qt6-5compat: An out-of-bounds read (buffer over-read) vulnerability exists in QTextCodec::codecForName() in Qt CVE-2026-9499 is fixed in 15 products on 1 platform, first by RHSA-2026:72383, released July 21, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-9499 - Priority: High - CVSS: 7.5 (Important) - EPSS: 0.0030 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Jul 21, 2026 ## Description 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. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | qt5-qtbase RHEL 8 | 0:5.15.3-9.el8_10 | [RHSA-2026:65897](https://patchblox.com/security/data/fix/linux/rhsa-2026-65897.md) | Sep 13, 2026 | | Linux | qt5-qtbase RHEL 9 | 0:5.15.9-11.el9_8.1 | [RHSA-2026:65993](https://patchblox.com/security/data/fix/linux/rhsa-2026-65993.md) | Sep 13, 2026 | | Linux | qt5-qtbase almalinux 8 | 5.15.3-9.el8_10 | [ALSA-2026:65897](https://patchblox.com/security/data/fix/linux/alsa-2026-65897.md) | Sep 9, 2026 | | Linux | qt5-qtbase almalinux 9 | 5.15.9-11.el9_8.1 | [ALSA-2026:65993](https://patchblox.com/security/data/fix/linux/alsa-2026-65993.md) | Sep 9, 2026 | | Linux | qt5-qtbase ol 8 | 0:5.15.3-9.el8_10 | [ELSA-2026-65897-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65897-0.md) | Sep 9, 2026 | | Linux | qt5-qtbase ol 9 | 0:5.15.9-11.el9_8.1 | [ELSA-2026-65993-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65993-0.md) | Sep 9, 2026 | | Linux | qt5-qtbase rocky 8 | 0:5.15.3-9.el8_10 | [RLSA-2026:65897](https://patchblox.com/security/data/fix/linux/rlsa-2026-65897.md) | Sep 10, 2026 | | Linux | qt5-qtbase rocky 9 | 0:5.15.9-11.el9_8.1 | [RLSA-2026:65993](https://patchblox.com/security/data/fix/linux/rlsa-2026-65993.md) | Sep 10, 2026 | | Linux | qt5-qtbase-common RHEL 8 | 0:5.15.3-9.el8_10 | [RHSA-2026:65897](https://patchblox.com/security/data/fix/linux/rhsa-2026-65897.md) | Sep 13, 2026 | | Linux | qt5-qtbase-common RHEL 9 | 0:5.15.9-11.el9_8.1 | [RHSA-2026:65993](https://patchblox.com/security/data/fix/linux/rhsa-2026-65993.md) | Sep 13, 2026 | | Linux | qt5-qtbase-common almalinux 8 | 5.15.3-9.el8_10 | [ALSA-2026:65897](https://patchblox.com/security/data/fix/linux/alsa-2026-65897.md) | Sep 9, 2026 | | Linux | qt5-qtbase-common almalinux 9 | 5.15.9-11.el9_8.1 | [ALSA-2026:65993](https://patchblox.com/security/data/fix/linux/alsa-2026-65993.md) | Sep 9, 2026 | | Linux | qt5-qtbase-common ol 8 | 0:5.15.3-9.el8_10 | [ELSA-2026-65897-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65897-0.md) | Sep 9, 2026 | | Linux | qt5-qtbase-common ol 9 | 0:5.15.9-11.el9_8.1 | [ELSA-2026-65993-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65993-0.md) | Sep 9, 2026 | | Linux | qt5-qtbase-devel RHEL 8 | 0:5.15.3-9.el8_10 | [RHSA-2026:65897](https://patchblox.com/security/data/fix/linux/rhsa-2026-65897.md) | Sep 13, 2026 | | Linux | qt5-qtbase-devel RHEL 9 | 0:5.15.9-11.el9_8.1 | [RHSA-2026:65993](https://patchblox.com/security/data/fix/linux/rhsa-2026-65993.md) | Sep 13, 2026 | | Linux | qt5-qtbase-devel almalinux 8 | 5.15.3-9.el8_10 | [ALSA-2026:65897](https://patchblox.com/security/data/fix/linux/alsa-2026-65897.md) | Sep 9, 2026 | | Linux | qt5-qtbase-devel almalinux 9 | 5.15.9-11.el9_8.1 | [ALSA-2026:65993](https://patchblox.com/security/data/fix/linux/alsa-2026-65993.md) | Sep 9, 2026 | | Linux | qt5-qtbase-devel ol 8 | 0:5.15.3-9.el8_10 | [ELSA-2026-65897-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65897-0.md) | Sep 9, 2026 | | Linux | qt5-qtbase-devel ol 9 | 0:5.15.9-11.el9_8.1 | [ELSA-2026-65993-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65993-0.md) | Sep 9, 2026 | | Linux | qt5-qtbase-examples RHEL 8 | 0:5.15.3-9.el8_10 | [RHSA-2026:65897](https://patchblox.com/security/data/fix/linux/rhsa-2026-65897.md) | Sep 13, 2026 | | Linux | qt5-qtbase-examples RHEL 9 | 0:5.15.9-11.el9_8.1 | [RHSA-2026:65993](https://patchblox.com/security/data/fix/linux/rhsa-2026-65993.md) | Sep 13, 2026 | | Linux | qt5-qtbase-examples almalinux 8 | 5.15.3-9.el8_10 | [ALSA-2026:65897](https://patchblox.com/security/data/fix/linux/alsa-2026-65897.md) | Sep 9, 2026 | | Linux | qt5-qtbase-examples almalinux 9 | 5.15.9-11.el9_8.1 | [ALSA-2026:65993](https://patchblox.com/security/data/fix/linux/alsa-2026-65993.md) | Sep 9, 2026 | | Linux | qt5-qtbase-examples ol 8 | 0:5.15.3-9.el8_10 | [ELSA-2026-65897-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65897-0.md) | Sep 9, 2026 | | Linux | qt5-qtbase-examples ol 9 | 0:5.15.9-11.el9_8.1 | [ELSA-2026-65993-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65993-0.md) | Sep 9, 2026 | | Linux | qt5-qtbase-gui RHEL 8 | 0:5.15.3-9.el8_10 | [RHSA-2026:65897](https://patchblox.com/security/data/fix/linux/rhsa-2026-65897.md) | Sep 13, 2026 | | Linux | qt5-qtbase-gui RHEL 9 | 0:5.15.9-11.el9_8.1 | [RHSA-2026:65993](https://patchblox.com/security/data/fix/linux/rhsa-2026-65993.md) | Sep 13, 2026 | | Linux | qt5-qtbase-gui almalinux 8 | 5.15.3-9.el8_10 | [ALSA-2026:65897](https://patchblox.com/security/data/fix/linux/alsa-2026-65897.md) | Sep 9, 2026 | | Linux | qt5-qtbase-gui almalinux 9 | 5.15.9-11.el9_8.1 | [ALSA-2026:65993](https://patchblox.com/security/data/fix/linux/alsa-2026-65993.md) | Sep 9, 2026 | | Linux | qt5-qtbase-gui ol 8 | 0:5.15.3-9.el8_10 | [ELSA-2026-65897-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65897-0.md) | Sep 9, 2026 | | Linux | qt5-qtbase-gui ol 9 | 0:5.15.9-11.el9_8.1 | [ELSA-2026-65993-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65993-0.md) | Sep 9, 2026 | | Linux | qt5-qtbase-mysql RHEL 8 | 0:5.15.3-9.el8_10 | [RHSA-2026:65897](https://patchblox.com/security/data/fix/linux/rhsa-2026-65897.md) | Sep 13, 2026 | | Linux | qt5-qtbase-mysql RHEL 9 | 0:5.15.9-11.el9_8.1 | [RHSA-2026:65993](https://patchblox.com/security/data/fix/linux/rhsa-2026-65993.md) | Sep 13, 2026 | | Linux | qt5-qtbase-mysql almalinux 8 | 5.15.3-9.el8_10 | [ALSA-2026:65897](https://patchblox.com/security/data/fix/linux/alsa-2026-65897.md) | Sep 9, 2026 | | Linux | qt5-qtbase-mysql almalinux 9 | 5.15.9-11.el9_8.1 | [ALSA-2026:65993](https://patchblox.com/security/data/fix/linux/alsa-2026-65993.md) | Sep 9, 2026 | | Linux | qt5-qtbase-mysql ol 8 | 0:5.15.3-9.el8_10 | [ELSA-2026-65897-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65897-0.md) | Sep 9, 2026 | | Linux | qt5-qtbase-mysql ol 9 | 0:5.15.9-11.el9_8.1 | [ELSA-2026-65993-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65993-0.md) | Sep 9, 2026 | | Linux | qt5-qtbase-odbc RHEL 8 | 0:5.15.3-9.el8_10 | [RHSA-2026:65897](https://patchblox.com/security/data/fix/linux/rhsa-2026-65897.md) | Sep 13, 2026 | | Linux | qt5-qtbase-odbc RHEL 9 | 0:5.15.9-11.el9_8.1 | [RHSA-2026:65993](https://patchblox.com/security/data/fix/linux/rhsa-2026-65993.md) | Sep 13, 2026 | | Linux | qt5-qtbase-odbc almalinux 8 | 5.15.3-9.el8_10 | [ALSA-2026:65897](https://patchblox.com/security/data/fix/linux/alsa-2026-65897.md) | Sep 9, 2026 | | Linux | qt5-qtbase-odbc almalinux 9 | 5.15.9-11.el9_8.1 | [ALSA-2026:65993](https://patchblox.com/security/data/fix/linux/alsa-2026-65993.md) | Sep 9, 2026 | | Linux | qt5-qtbase-odbc ol 8 | 0:5.15.3-9.el8_10 | [ELSA-2026-65897-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65897-0.md) | Sep 9, 2026 | | Linux | qt5-qtbase-odbc ol 9 | 0:5.15.9-11.el9_8.1 | [ELSA-2026-65993-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65993-0.md) | Sep 9, 2026 | | Linux | qt5-qtbase-postgresql RHEL 8 | 0:5.15.3-9.el8_10 | [RHSA-2026:65897](https://patchblox.com/security/data/fix/linux/rhsa-2026-65897.md) | Sep 13, 2026 | | Linux | qt5-qtbase-postgresql RHEL 9 | 0:5.15.9-11.el9_8.1 | [RHSA-2026:65993](https://patchblox.com/security/data/fix/linux/rhsa-2026-65993.md) | Sep 13, 2026 | | Linux | qt5-qtbase-postgresql almalinux 8 | 5.15.3-9.el8_10 | [ALSA-2026:65897](https://patchblox.com/security/data/fix/linux/alsa-2026-65897.md) | Sep 9, 2026 | | Linux | qt5-qtbase-postgresql almalinux 9 | 5.15.9-11.el9_8.1 | [ALSA-2026:65993](https://patchblox.com/security/data/fix/linux/alsa-2026-65993.md) | Sep 9, 2026 | | Linux | qt5-qtbase-postgresql ol 8 | 0:5.15.3-9.el8_10 | [ELSA-2026-65897-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65897-0.md) | Sep 9, 2026 | | Linux | qt5-qtbase-postgresql ol 9 | 0:5.15.9-11.el9_8.1 | [ELSA-2026-65993-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65993-0.md) | Sep 9, 2026 | | Linux | qt5-qtbase-private-devel RHEL 8 | 0:5.15.3-9.el8_10 | [RHSA-2026:65897](https://patchblox.com/security/data/fix/linux/rhsa-2026-65897.md) | Sep 13, 2026 | | Linux | qt5-qtbase-private-devel RHEL 9 | 0:5.15.9-11.el9_8.1 | [RHSA-2026:65993](https://patchblox.com/security/data/fix/linux/rhsa-2026-65993.md) | Sep 13, 2026 | | Linux | qt5-qtbase-private-devel almalinux 8 | 5.15.3-9.el8_10 | [ALSA-2026:65897](https://patchblox.com/security/data/fix/linux/alsa-2026-65897.md) | Sep 9, 2026 | | Linux | qt5-qtbase-private-devel almalinux 9 | 5.15.9-11.el9_8.1 | [ALSA-2026:65993](https://patchblox.com/security/data/fix/linux/alsa-2026-65993.md) | Sep 9, 2026 | | Linux | qt5-qtbase-private-devel ol 8 | 0:5.15.3-9.el8_10 | [ELSA-2026-65897-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65897-0.md) | Sep 9, 2026 | | Linux | qt5-qtbase-private-devel ol 9 | 0:5.15.9-11.el9_8.1 | [ELSA-2026-65993-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65993-0.md) | Sep 9, 2026 | | Linux | qt5-qtbase-static RHEL 8 | 0:5.15.3-9.el8_10 | [RHSA-2026:65897](https://patchblox.com/security/data/fix/linux/rhsa-2026-65897.md) | Sep 13, 2026 | | Linux | qt5-qtbase-static RHEL 9 | 0:5.15.9-11.el9_8.1 | [RHSA-2026:65993](https://patchblox.com/security/data/fix/linux/rhsa-2026-65993.md) | Sep 13, 2026 | | Linux | qt5-qtbase-static almalinux 8 | 5.15.3-9.el8_10 | [ALSA-2026:65897](https://patchblox.com/security/data/fix/linux/alsa-2026-65897.md) | Sep 9, 2026 | | Linux | qt5-qtbase-static almalinux 9 | 5.15.9-11.el9_8.1 | [ALSA-2026:65993](https://patchblox.com/security/data/fix/linux/alsa-2026-65993.md) | Sep 9, 2026 | | Linux | qt5-qtbase-static ol 8 | 0:5.15.3-9.el8_10 | [ELSA-2026-65897-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65897-0.md) | Sep 9, 2026 | | Linux | qt5-qtbase-static ol 9 | 0:5.15.9-11.el9_8.1 | [ELSA-2026-65993-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65993-0.md) | Sep 9, 2026 | | Linux | qt6-5compat Debian 14 | 6.10.2-4 | [DEBIAN-CVE-2026-9499](https://patchblox.com/security/data/fix/linux/debian-cve-2026-9499.md) | Jul 31, 2026 | | Linux | qt6-qt5compat RHEL 10 | 6.8.1-1.el10_0.1 | [RHSA-2026:72383](https://patchblox.com/security/data/fix/linux/rhsa-2026-72383.md) | Jul 21, 2026 | | Linux | qt6-qt5compat almalinux 10 | 6.10.1-1.el10_2.1 | [ALSA-2026:65816](https://patchblox.com/security/data/fix/linux/alsa-2026-65816.md) | Sep 9, 2026 | | Linux | qt6-qt5compat ol 10 | 0:6.10.1-1.el10_2.1 | [ELSA-2026-65816-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65816-0.md) | Sep 9, 2026 | | Linux | qt6-qt5compat rocky 10 | 0:6.10.1-1.el10_2.1 | [RLSA-2026:65816](https://patchblox.com/security/data/fix/linux/rlsa-2026-65816.md) | Sep 9, 2026 | | Linux | qt6-qt5compat-devel almalinux 10 | 6.10.1-1.el10_2.1 | [ALSA-2026:65816](https://patchblox.com/security/data/fix/linux/alsa-2026-65816.md) | Sep 9, 2026 | | Linux | qt6-qt5compat-devel ol 10 | 0:6.10.1-1.el10_2.1 | [ELSA-2026-65816-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65816-0.md) | Sep 9, 2026 | | Linux | qt6-qt5compat-examples almalinux 10 | 6.10.1-1.el10_2.1 | [ALSA-2026:65816](https://patchblox.com/security/data/fix/linux/alsa-2026-65816.md) | Sep 9, 2026 | | Linux | qt6-qt5compat-examples ol 10 | 0:6.10.1-1.el10_2.1 | [ELSA-2026-65816-0](https://patchblox.com/security/data/fix/linux/elsa-2026-65816-0.md) | Sep 9, 2026 | | Linux | qtbase-opensource-src Debian 14 | 5.15.19+dfsg-4 | [DEBIAN-CVE-2026-9499](https://patchblox.com/security/data/fix/linux/debian-cve-2026-9499.md) | Jul 31, 2026 | --- Data as of 2026-11-08T06:59:42Z UTC. 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