CVE-2026-95509 PUBLISHED

Out-of-bounds read vulnerability in string formatting impacts Qt for MCUs

Assigner: Qt
Reserved: 22.09.2026 Published: 29.09.2026 Updated: 29.09.2026

Strings optimized for Latin-1 displaying Latin-1 characters cause incorrect String.arg() formatting by an incorrect buffer size calculation, causing out-of-bounds reading.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N
CVSS Score: 8.8

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	Low	Confidentiality	None
Attack Complexity	Low	Integrity	Low	Integrity	None
Attack Requirements	None	Availability	High	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

Product Status

Vendor	qt
Product	Qt for MCUs
Versions	Default: unaffected affected from 2.6.0 to 2.11.3 (excl.) affected from 2.12.0 to 2.12.3 (excl.)

References

https://wiki.qt.io/List_of_known_vulnerabilities_in_Qt_products#CVE-2026-95509:

Problem Types

CWE-125 Out-of-bounds Read CWE
CWE-131 Incorrect Calculation of Buffer Size CWE

Impacts

CAPEC-540 Overread Buffers
CAPEC-47 Buffer Overflow via Parameter Expansion