CVE-2026-103645

Integer overflow vulnerability in QTextCodec fromUnicode() and toUnicode() impacts Qt

Published Nov 13, 2026 CVSS 4.0 · 1.1 Low EPSS n/a KEV · Not listed

Description

An integer overflow vulnerability in the Qt QTextCodec fromUnicode() and toUnicode() functionality of the Qt 5 Core Compatibility APIs module (Qt 6) and the Qt Core module (Qt 5). Only builds where Qt is compiled with ICU support are affected.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

unaffected

Version	Status	Constraints
`0`	unknown	< 5.0.0
`5.0.0`	affected	< 6.8.9
`6.9.0`	affected	< 6.11.3

No data.

No data available yet.

Remediation

No solution or workaround provided in the CVE record

Tracking

Advisories

No advisories available

Metrics

Attack Vector Local

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction Passive

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact Low

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

References

Link	Providers
https://codereview.qt-project.org/c/qt/qt5compat/+/762795
https://www.qt.io/security-advisories?search=CVE-2026-103645

History

Nov 13, 2026 9:45 AM Description updated. Title updated. First appearance in the feed. Weaknesses updated. Affected versions updated. Affected vendors updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		An integer overflow vulnerability in the Qt QTextCodec fromUnicode() and toUnicode() functionality of the Qt 5 Core Compatibility APIs module (Qt 6) and the Qt Core module (Qt 5). Only builds where Qt is compiled with ICU support are affected.
Title		Integer overflow vulnerability in QTextCodec fromUnicode() and toUnicode() impacts Qt
First Time appeared		Qt Qt qt Qt qt5compat Qt qtbase
Weaknesses		CWE-190 CWE-835
CPEs		cpe:2.3:a:qt:qt5compat:::::::: cpe:2.3:a:qt:qt:::::::: cpe:2.3:a:qt:qtbase::::::::
Vendors & Products		Qt Qt qt Qt qt5compat Qt qtbase
References		https://codereview.qt-project.org/c/qt/qt5compat/+/762795 https://www.qt.io/security-advisories?search=CVE-2026-103645
Metrics		cvssV4_0 `{'score': 1.1, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/R:U/U:Clear'}`