Description
Blosc c-blosc2 before 3.5.0 contains a divide-by-zero vulnerability in blosc2_schunk_get_slice_buffer() in blosc/schunk.c that allows attackers to crash applications by supplying crafted frames with unchecked zero chunksize or blocksize values. Attackers can provide a malicious Blosc2 frame opened via blosc2_schunk_open() or blosc2_schunk_from_buffer() and read as a slice, raising SIGFPE and terminating the process.
Metrics
CVSS 3.1 5.5/10
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:HWeakness enumeration
Affected software
Source: the vendor's advisory (CNA). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| Blosc | c-blosc2 | < 3.5.0 |
References
- https://github.com/Blosc/c-blosc2
- https://github.com/Blosc/c-blosc2/blob/v3.4.1/blosc/frame.c#L1214-L1227
- https://github.com/Blosc/c-blosc2/blob/v3.4.1/blosc/schunk.c#L1662-L1700
- https://github.com/Blosc/c-blosc2/commit/4fff1787408d94b895c6f9cb50f7925ad5919052
- https://github.com/Blosc/c-blosc2/issues/834
- https://hackmd.io/@haindpwn/c-blosc2-schunk-slice-divide-by-zero
- https://www.vulncheck.com/advisories/blosc-c-blosc2-before-3.5.0-divide-by-zero-via-blosc2-schunk-get-slice-buffer
- https://hackmd.io/@haindpwn/cve-2026-122330-c-blosc2-schunk-slice-divide-by-zero
Timeline
- Published
- Nov 5, 2026
- Last modified
- Nov 12, 2026
- NVD status
- Awaiting Analysis