An out-of-bounds read and integer underflow vulnerability in the 
QNdefNfcTextRecord class of the Qt NFC module (qtconnectivity) has been 
discovered and has been assigned the CVE id CVE-2026-13326.
[cid:1e7640cc-c8ea-411a-83d3-53ec3f98f45b]
 Affected versions: from Qt 5.2.0 to Qt 6.8.8, from Qt 6.9.0 to Qt 6.10.3, from 
Qt 6.11.0 to Qt 6.11.1

Impact: A malicious NFC tag can declare a language code length larger than the 
payload it actually contains.
When an application reads an NDEF text record, Qt NFC does not bounds-check the 
declared language code length against the actual size of the payload. The 
subtraction used to derive the remaining text length underflows, and the 
resulting oversized length is used to construct the string. The record is 
therefore read past the end of the payload buffer.
Exploitation requires the attacker's tag to be presented to the device in close 
proximity, and requires the user to tap the device to the tag. In the worst 
case the application terminates unexpectedly, resulting in a denial of service. 
Contents of adjacent memory may also be exposed as part of the returned string, 
giving a limited loss of confidentiality.

CVSS 4.0 Score: 6.9 / MEDIUM

Vector String: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N

Mitigation: Only tap NFC tags from trusted sources. Avoid reading unknown or 
untrusted NFC tags until the fix below has been applied.

Solution: Apply the following patch, or update to Qt 6.8.9, Qt 6.10.4 or Qt 
6.11.2 or later.

Patches:
Dev: https://codereview.qt-project.org/c/qt/qtconnectivity/+/743136
Qt 6.11: https://codereview.qt-project.org/c/qt/qtconnectivity/+/746284 or 
https://download.qt.io/official_releases/qt/6.11/CVE-2026-13326-qtconnectivity-6.11.diff
Qt 6.10: https://codereview.qt-project.org/c/qt/qtconnectivity/+/758862 or 
https://download.qt.io/official_releases/qt/6.10/CVE-2026-13326-qtconnectivity-6.10.diff
Qt 6.8: https://codereview.qt-project.org/c/qt/tqtc-qtconnectivity/+/747301 or 
https://download.qt.io/official_releases/qt/6.8/CVE-2026-13326-qtconnectivity-6.8.diff

Tero Pelkonen
Qt Group

Confidential
_______________________________________________
Announce mailing list
[email protected]
https://lists.qt-project.org/listinfo/announce
-- 
Development mailing list
[email protected]
https://lists.qt-project.org/listinfo/development

Reply via email to