Vulnerability · Published Feb 19, 2026 · Assigned by fedora

CVE-2026-2681Github.com/supranational/blst: blst cryptographic library: denial of service via out-of-bounds stack write in key generation

Medium 5.3

In plain English

A medium-severity out-of-bounds write in blst. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 29% of all known vulnerabilities).

Severity (CVSS 3.1)5.3Medium

Exploit odds (30 days)0.3%top 71.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
	blst	0 – through 0.3.16

Weakness: CWE-787 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References

https://access.redhat.com/security/cve/CVE-2026-2681 vdb-entry, x_refsource_REDHAT
RHBZ#2440580 issue-tracking, x_refsource_REDHAT