Out-of-bounds read vulnerability in string formatting impacts Qt for MCUs (CVE-2026-95509) | HOL Guard CVE

High · CVSS 8.8CVE-2026-95509

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

Answer in brief

CVE-2026-95509 records a High severity (CVSS 8.8) vulnerability in Out-of-bounds read vulnerability in string formatting impacts Qt for MCUs. The current sources do not mark it as known exploited. The current feed maps qt/Qt for MCUs (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 29, 2026Updated Sep 29, 2026Source checked Sep 29, 2026First seen by HOL Sep 29, 2026Material review Sep 29, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.8
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 8.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps qt/Qt for MCUs (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
qt/Qt for MCUsgeneric	>=2.6.0 <2.11.3 \|\| >=2.12.0 <2.12.3	2.11.3, 2.12.3

Recommended response

Check inventory. Check lockfiles and deployed manifests for qt/Qt for MCUs.
Review the reported fix. Update qt/Qt for MCUs to 2.11.3 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 29, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 29, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 29, 2026

Sources and claim methodology

Source referencewiki.qt.io

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.