Blosc C-Blosc2 blosclz Decompression blosclz.c blosclz_decompress integer overflow (CVE-2026-103222) | HOL Guard CVE

Medium · CVSS 6.3CVE-2026-103222

Blosc C-Blosc2 blosclz Decompression blosclz.c blosclz_decompress integer overflow

Answer in brief

CVE-2026-103222 records a Medium severity (CVSS 6.3) vulnerability in Blosc C-Blosc2 blosclz Decompression blosclz.c blosclz_decompress integer overflow. The current sources do not mark it as known exploited. The current feed maps Blosc/C-Blosc2 (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 30, 2026Updated Sep 30, 2026Source checked Sep 30, 2026First seen by HOL Sep 30, 2026Material review Sep 30, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 6.3
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

CVSS is 6.3. 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 Blosc/C-Blosc2 (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Blosc/C-Blosc2generic	3.3.0 \|\| 3.3.1 \|\| 3.3.2	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Blosc/C-Blosc2.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 30, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 30, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 30, 2026

Sources and claim methodology

Upstream source description

A vulnerability was determined in Blosc C-Blosc2 up to 3.3.2. This impacts the function blosclz_decompress of the file blosc/blosclz.c of the component blosclz Decompression. Executing a manipulation can lead to integer overflow. The attack may be launched remotely. A high complexity level is associated with this attack. The exploitability is said to be difficult. Upgrading to version 3.3.3 will fix this issue. This patch is called fe2964d114d97847f56570a0ab2be2c57ccbeedc. The affected component should be upgraded.

Quoted source text, attributed separately from HOL analysis.