CVE-2026-58262: Klever-Go: PubKeysBitmap padding bits bypass the BLS signature quorum
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 Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Klever-Goto a version that resolves this vulnerability.Fixed in 1.7.20
Event History
Frequently Asked Questions
What is the severity of CVE-2026-58262?
CVE-2026-58262 has a risk rating of 62, indicating a moderate level of severity.
How do I fix CVE-2026-58262?
To address CVE-2026-58262, update to Klever-Go version 1.7.20 or later, where the padding bits issue is resolved.
What impact does CVE-2026-58262 have on Klever-Go?
CVE-2026-58262 allows unused padding bits in the PubKeysBitmap to be counted towards the validator quorum, potentially compromising security.
Who is affected by CVE-2026-58262?
Users and operators of Klever-Go prior to version 1.7.20 are affected by CVE-2026-58262.
What procedures should be followed after addressing CVE-2026-58262?
After updating Klever-Go to a secure version, verify the correct functionality of header signature verification.