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

> Attackers can hijack accounts and steal assets by exploiting a permission check that trusts attacker-controlled recipient addresses instead of the authenticated caller.

- **Severity:** High 8.7 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 23 Sep 2026
- **Updated:** 24 Sep 2026
- **Also known as:** GHSA-97cv-x867-6xhm, GO-2026-6582

## What is CVE-2026-82405?

CVE-2026-82405 is a high-severity authentication bypass vulnerability in klever-io klever-go, published on 23 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official 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.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2026-82405?

3 open source packages ship an affected version, including github.com/klever-io/klever-go.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/klever-io/klever-go` | Go | All versions | 1.7.20 |
| `github.com/klever-io/klever-go` | Go | All versions | 1.7.20 |
| `github.com/klever-io/klever-go` | Go | All versions | 1.7.20 |

## How do I fix CVE-2026-82405?

Upgrade github.com/klever-io/klever-go to 1.7.20 or later.

## Is CVE-2026-82405 being exploited?

There is no known exploitation of CVE-2026-82405 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-82405 and fix it if it is affected.

What it is: CVE-2026-82405 is a high-severity authentication bypass vulnerability in klever-io klever-go, published on 23 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-82405 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/klever-io/klever-go (Go): affected all versions; fixed in 1.7.20
- github.com/klever-io/klever-go (Go): affected all versions; fixed in 1.7.20
- github.com/klever-io/klever-go (Go): affected all versions; fixed in 1.7.20

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-82405/ (Markdown: https://insights.sbomify.com/CVE-2026-82405/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-82405
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-82405
- OSV: https://osv.dev/vulnerability/CVE-2026-82405

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-82405/
Summaries are generated and may contain mistakes; the official description above is the record.