VulnerabilityDeferred

CVE-2026-58262

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…

HIGH 7.1EPSS 0.12%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.12%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 4.0: 7.1 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.12% probability · 2th percentile
CISA KEV: Not listed
Weakness: CWE-345, CWE-347
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.