CVE-2026-2681

CVE-2026-2681

A flaw was found in the blst cryptographic library. This out-of-bounds stack write vulnerability, specifically in the blst_sha256_bcopy assembly routine, occurs due to a missing zero-length guard. A remote attacker can exploit this by providing a zero-length salt parameter to key generation functions, such as blst_keygen_v5(), if the application exposes this functionality. Successful exploitation leads to memory corruption and immediate process termination, resulting in a denial-of-service (DoS) condition.

Vulnerability class: Buffer Overflow

EPSS: 0.003 (22.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-2681?
CVE-2026-2681 is a medium-severity vulnerability, classified under Out-of-bounds Write. CVSS score: 5.3/10. Published 2026-02-19.
How severe is CVE-2026-2681?
Medium severity. CVSS v3 base score is 5.3 out of 10.