CVE-2026-58262
Klever-Go: PubKeysBitmap padding bits bypass the BLS signature quorum
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.
INFO
Published Date :
Aug. 7, 2026, 10:16 p.m.
Last Modified :
Oct. 24, 2026, 4:10 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-58262
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update Klever-Go to version 1.7.20 or later.
- Ensure header signature verification logic is corrected.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-58262.
| URL | Resource |
|---|---|
| https://github.com/klever-io/klever-go/commit/a11cb28e495e608d8034dbe83a91e89d0c68e0f7 | |
| https://github.com/klever-io/klever-go/security/advisories/GHSA-f9h7-4mmq-vgcq |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-58262 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-58262
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-58262 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-58262 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Oct. 24, 2026
Action Type Old Value New Value Changed Translation Title: klever-go de klever-io, Description: Klever-Go es la implementación en Go del protocolo de cadena de bloques Klever. Antes de la versión 1.7.20, la verificación de la firma de la cabecera cuenta los bits de relleno no utilizados de PubKeysBitmap para el quórum de validadores de dos tercios. Estos bits de relleno no corresponden a ningún validador y son ignorados por la verificación real de la firma agregada BLS, por lo que un productor de bloques malicioso o comprometido puede configurarlos para alcanzar el quórum requerido mientras reúne menos firmas de validadores genuinas de las que exige el protocolo. Como resultado, los nodos que importan o interceptan la cabecera la aceptan como correctamente firmada sin un quórum real de dos tercios, debilitando la seguridad del consenso y socavando la finalidad. Este problema se corrige en la versión 1.7.20. Title: klever-go de klever-io, Description: Klever-Go es la implementación en Go del protocolo de cadena de bloques Klever. Antes de la versión 1.7.20, la verificación de la firma de la cabecera cuenta los bits de relleno no utilizados de PubKeysBitmap para el quórum de validadores de dos tercios. Estos bits de relleno no corresponden a ningún validador y son ignorados por la verificación real de la firma agregada BLS, por lo que un productor de bloques malicioso o comprometido puede configurarlos para alcanzar el quórum requerido mientras reúne menos firmas de validadores genuinas de las que exige el protocolo. Como resultado, los nodos que importan o interceptan la cabecera la aceptan como correctamente firmada sin un quórum real de dos tercios, debilitando la seguridad del consenso y socavando la finalidad. Este problema se corrige en la versión 1.7.20. -
CVE Translated by [email protected]
Oct. 23, 2026
Action Type Old Value New Value Added Translation Title: klever-go de klever-io, Description: Klever-Go es la implementación en Go del protocolo de cadena de bloques Klever. Antes de la versión 1.7.20, la verificación de la firma de la cabecera cuenta los bits de relleno no utilizados de PubKeysBitmap para el quórum de validadores de dos tercios. Estos bits de relleno no corresponden a ningún validador y son ignorados por la verificación real de la firma agregada BLS, por lo que un productor de bloques malicioso o comprometido puede configurarlos para alcanzar el quórum requerido mientras reúne menos firmas de validadores genuinas de las que exige el protocolo. Como resultado, los nodos que importan o interceptan la cabecera la aceptan como correctamente firmada sin un quórum real de dos tercios, debilitando la seguridad del consenso y socavando la finalidad. Este problema se corrige en la versión 1.7.20. -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 12, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-58262', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-12T22:08:08.809887Z'} -
New CVE Received by [email protected]
Aug. 07, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'klever-io', 'product': 'klever-go', 'versions': [{'status': 'affected', 'version': '< 1.7.20'}]}] Added 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. Added CVSS V4.0 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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-345 Added CWE CWE-347 Added Reference https://github.com/klever-io/klever-go/commit/a11cb28e495e608d8034dbe83a91e89d0c68e0f7 Added Reference https://github.com/klever-io/klever-go/security/advisories/GHSA-f9h7-4mmq-vgcq