CVE-2026-103653
Out-of-bounds read vulnerability in CoAP message parsing impacts Qt CoAP
An out-of-bounds read vulnerability in the Qt CoAP message parsing (QCoapInternalReply::createFromFrame()) of the Qt CoAP module. Processing a malformed CoAP message can cause an application using Qt CoAP to crash (loss of availability) or to continue operating on incorrect data (potential loss of integrity).
Fixes and workarounds
Fix
The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.
Source: CNA: QtFix
The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.
Source: CNA: QtAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| Qt qt |
≥ 5.13.0; ≤ 6.8.8 (affected, python) ≥ 6.9.0; ≤ 6.11.2 (affected, python) ≥ 0; < 5.13.0 (unaffected, python) Other versions: unaffected |
CNA: Qt |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 6.7 medium |
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:U/AU:Y/R:U/RE:L/U:Amber | CNA: Qt |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://wiki.qt.io/List_of_known_vulnerabilities_in_Qt_products#CVE-2026-103653:CNA: Qt · vendor-advisory
- https://codereview.qt-project.org/c/qt/qtcoap/+/760652CNA: Qt · patch
- https://codereview.qt-project.org/c/qt/qtcoap/+/761120CNA: Qt · patch
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