Is CVE-2026-103653 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-103653 being exploited in the wild.

How severe is CVE-2026-103653?

Informational severity, published 3 November 2026.

Is there a fix for CVE-2026-103653?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-103653 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-103653?

Check whether you run Qt CoAP. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-103653: Qt CoAP out-of-bounds read in message parsing

CVE-2026-103653 · Severity: info · Published 2026-11-03

Qt CoAP is a library for building applications that use the Constrained Application Protocol (CoAP) to communicate with IoT devices and servers. A flaw in how it parses CoAP messages can cause applications to crash or operate with corrupted data if they receive a specially crafted malformed message.

Vendors: Qt.

Quick answers

Is CVE-2026-103653 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-103653 being exploited in the wild.
How severe is CVE-2026-103653?: Informational severity, published 3 November 2026.
Which products and versions are affected?: Qt Qt CoAP.
Is there a fix for CVE-2026-103653?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-103653 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-103653?: Check whether you run Qt CoAP. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

An out-of-bounds read vulnerability exists in QCoapInternalReply::createFromFrame() during CoAP message parsing. Processing a malformed CoAP message triggers the out-of-bounds read, leading to either a denial of service (crash) or potential data corruption. No authentication or user interaction is required; a network-adjacent attacker can send a malicious CoAP packet to trigger the flaw.

Affected products

Qt Qt CoAP

Timeline

2026-11-03: disclosed

References

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