# Klever-Go: Validator registration accepts an unvalidated BLS public key → consensus liveness DoS

Advisory record · `GHSA-9wh6-9hq7-9688`

- **Identifiers:** `GHSA-9wh6-9hq7-9688` · `CVE-2026-82407` · `GO-2026-6586`
- **State:** Confirmed
- **Severity:** CVSS 7.0 High
- **Critical:** No
- **Weakness (CWE):** [CWE-20](https://cwe.mitre.org/data/definitions/20.html)
- **Tags:** [CWE-20](https://agentprime.io/advisories/tag/cwe-20.md)
- **Published:** 23 Sept 2026
- **Updated:** 1 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 23 Sept 2026, 21:24 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `github.com/klever-io/klever-go` (Go): affected `<1.7.20`; fixed in `1.7.20`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> Klever-Go versions before 1.7.20 accept validator registration with a malformed BLS public key. Anyone who can stake the minimum validator amount can register such a key, and when that validator is selected into a consensus group, block production fails for those rounds. Upgrade to version 1.7.20.

Written 1 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 7.0 High, CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0047, the 40th percentile, on 8 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:12 UTC: First seen by agentprime
- 31 Oct 2026, 14:12 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-9wh6-9hq7-9688)

## Sources

- [GitHub Advisory Database: GHSA-9wh6-9hq7-9688](https://github.com/advisories/GHSA-9wh6-9hq7-9688)
- [OSV: GHSA-9wh6-9hq7-9688](https://osv.dev/vulnerability/GHSA-9wh6-9hq7-9688)
- <https://github.com/klever-io/klever-go/security/advisories/GHSA-9wh6-9hq7-9688>
- <https://github.com/klever-io/klever-go/commit/11606a90ccc289f93d0175994733229b332d9cff>
- <https://github.com/klever-io/klever-go/commit/642da967893884d635986fed3c43bdc679cbfe8f>
- <https://github.com/klever-io/klever-go>
- <https://github.com/klever-io/klever-go/releases/tag/v1.7.20>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-9wh6-9hq7-9688>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-9wh6-9hq7-9688/>. Everything for agents: <https://agentprime.io/llms.txt>.