CVE-2026-103645

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

Low 1.1

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.

Key facts

Published: 13 Nov 2026
Last changed: 13 Nov 2026
Assigned by: Qt
EPSS: 0.172% likely to be exploited in the next 30 days, higher than 6.658% of CVEs (scores for 15 Nov 2026)

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

1.1CVSS 4.0, Lowfrom the CNA (Qt)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

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

CAPEC-92 Forced Integer Overflow (CNA impact statement)

No explicit remediation statement is available on this page yet. Consult the original record and vendor references before choosing a fix.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

Read the original CVE record.

Affected products

Vendor	Product	Versions
qt	qt	Default status: unaffected 0 up to but excluding 5.0.0 (unknown) 5.0.0 up to but excluding 6.8.9 (affected) 6.9.0 up to but excluding 6.11.3 (affected)