Integer overflow in Blosc C-Blosc2
CVE-2026-103222
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.6 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Blosc C-Blosc2 — versions 3.3.0, 3.3.1, 3.3.2
Weakness classification (CWE)
References
- vuldb.com/vuln/411905 (technical-description, vdb-entry)
- vuldb.com/vuln/411905/cti (signature, permissions-required)
- vuldb.com/cve/CVE-2026-103222 (third-party-advisory)
- vuldb.com/submit/954976 (third-party-advisory)
- github.com/Blosc/c-blosc2/commit/fe2964d114d97847f56570a0ab2be2c57ccbeedc (patch)
- github.com/Blosc/c-blosc2/releases/tag/v3.3.3 (patch)
- github.com/Blosc/c-blosc2/ (product)
Frequently asked questions
- What is CVE-2026-103222?
- CVE-2026-103222 is a medium-severity vulnerability in Blosc C-Blosc2, classified under CWE-189. CVSS score: 5.6/10. Published 2026-09-30.
- How severe is CVE-2026-103222?
- Medium severity. CVSS v3 base score is 5.6 out of 10.