Vulnerability · Published Oct 27, 2026 · Assigned by Qt
CVE-2026-105946Out-of-bounds read vulnerability in NTLM authentication handling impacts Qt
Medium 5.3
In plain English
A medium-severity out-of-bounds read in qt from qt. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 40% of all known vulnerabilities).
Official description
Out-of-bounds read in the QAuthenticator NTLM authentication handling in the Qt Network module in Qt Group Qt allows remote attackers to obtain sensitive information (heap memory contents) or cause a denial of service (application crash) via a crafted NTLM challenge sent by a malicious server or proxy, when an application using QNetworkAccessManager or QTcpSocket authenticates with NTLM.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu:22.04:LTS | qt6-base | no fix listed | UBUNTU-CVE-2026-105946 |
| Ubuntu:24.04:LTS | qt6-base | no fix listed | UBUNTU-CVE-2026-105946 |
| Ubuntu:26.04:LTS | qt6-base | no fix listed | UBUNTU-CVE-2026-105946 |
| Ubuntu:26.10 | qt6-base | no fix listed | UBUNTU-CVE-2026-105946 |
| Ubuntu:26.04:LTS | qtbase-opensource-src | no fix listed | UBUNTU-CVE-2026-105946 |
| Ubuntu:26.10 | qtbase-opensource-src | no fix listed | UBUNTU-CVE-2026-105946 |
Affected products (as reported)
Weakness: CWE-125 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N/E:P