CVE-2026-122330: medium-severity vulnerability in Blosc c-blosc2
Blosc c-blosc2 before 3.5.0 Divide-by-Zero via blosc2_schunk_get_slice_buffer()
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
33Vexday Risk Score
No sign of exploitation. It has a public proof of concept.
ssvc Attendcvss 6.8epss 0.2%
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.
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Affected products
Blosc · c-blosc2public PoCs found — 1
cve_referencehackmd.io/@haindpwn/cve-2026-122330-c-blosc2-schunk-slice-divide-by-zerounverified⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
References
https://github.com/Blosc/c-blosc2https://github.com/Blosc/c-blosc2/blob/v3.4.1/blosc/frame.c#L1214-L1227https://github.com/Blosc/c-blosc2/blob/v3.4.1/blosc/schunk.c#L1662-L1700https://github.com/Blosc/c-blosc2/commit/4fff1787408d94b895c6f9cb50f7925ad5919052https://github.com/Blosc/c-blosc2/issues/834https://hackmd.io/@haindpwn/c-blosc2-schunk-slice-divide-by-zerohttps://hackmd.io/@haindpwn/cve-2026-122330-c-blosc2-schunk-slice-divide-by-zerohttps://www.vulncheck.com/advisories/blosc-c-blosc2-before-3.5.0-divide-by-zero-via-blosc2-schunk-get-slice-buffer