What is CVE-2020-29367?

CVE-2020-29367 is a high-severity vulnerability in Blosc C-Blosc2, classified under Out-of-bounds Write. CVSS score: 7.8/10. Published 2020-11-27.

How severe is CVE-2020-29367?

High severity. CVSS v3 base score is 7.8 out of 10.

Buffer overflow in Blosc C-Blosc2

CVE-2020-29367

blosc2.c in Blosc C-Blosc2 through 2.0.0.beta.5 has a heap-based buffer overflow when there is a lack of space to write compressed data.

Vulnerability class: Buffer Overflow

Published 2020-11-27 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.012 (67.0th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 67th percentile — 67.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000

Affected products

Blosc C-Blosc2 — versions 2.0.0

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

github.com/Blosc/c-blosc2/commit/c4c6470e88210afc95262c8b9fcc27e30ca043ee (Patch, Third Party Advisory)
bugs.chromium.org/p/oss-fuzz/issues/detail (Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2020-29367?: CVE-2020-29367 is a high-severity vulnerability in Blosc C-Blosc2, classified under Out-of-bounds Write. CVSS score: 7.8/10. Published 2020-11-27.
How severe is CVE-2020-29367?: High severity. CVSS v3 base score is 7.8 out of 10.