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.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
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
Which versions are affected by CVE-2026-82405?
3 open source packages ship an affected version, including github.com/klever-io/klever-go.
| Package | 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.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-82405 being exploited?
There is no known exploitation of CVE-2026-82405 in the wild and no public exploit code.
Sources
Also known as GHSA-97cv-x867-6xhm, GO-2026-6582.