blst up to 0.3.16 blst_keygen_v5 salt out-of-bounds write

Summaryinfo

A vulnerability, which was classified as critical, was found in blst up to 0.3.16. The affected element is the function blst_keygen_v5. Executing a manipulation of the argument salt can lead to out-of-bounds write. This vulnerability is handled as CVE-2026-2681. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability classified as critical was found in blst up to 0.3.16. This vulnerability affects the function blst_keygen_v5. The manipulation of the argument salt with an unknown input leads to a out-of-bounds write vulnerability. The CWE definition for the vulnerability is CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect availability. CVE summarizes:

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.

The advisory is available at access.redhat.com. This vulnerability was named CVE-2026-2681 since 02/18/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 02/19/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Name

• blst

Version

• 0.3.0
• 0.3.1
• 0.3.2
• 0.3.3
• 0.3.4
• 0.3.5
• 0.3.6
• 0.3.7
• 0.3.8
• 0.3.9
• 0.3.10
• 0.3.11
• 0.3.12
• 0.3.13
• 0.3.14
• 0.3.15
• 0.3.16

CPE 2.3info

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• 🔒
• 🔒

CPE 2.2info

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• 🔒
• 🔒

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