Vulnerability · Published Aug 7, 2026 · Assigned by GitHub_M
CVE-2026-58262Klever-Go: PubKeysBitmap padding bits bypass the BLS signature quorum
High 7.1
In plain English
A high-severity insufficient verification of data authenticity in klever-go from klever-io. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 5% of all known vulnerabilities).
Official description
Klever-Go is the Go implementation of the Klever blockchain protocol. Prior to 1.7.20, header signature verification counts the unused padding bits of the PubKeysBitmap toward the two-thirds validator quorum. These padding bits do not correspond to any validator and are ignored by the actual BLS aggregate-signature check, so a malicious or compromised block producer can set them to reach the required quorum while gathering fewer genuine validator signatures than the protocol demands. As a result, nodes that import or intercept the header accept it as correctly signed without a real two-thirds quorum, weakening consensus safety and undermining finality. This issue is fixed in version 1.7.20.
Affected products (as reported)
Weakness: CWE-345, CWE-347 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N