CVE-2026-82409 Klever-Go: Elasticsearch bulk / painless injection via on-chain account name -> explorer/indexer data forgery
Attackers can inject malicious JSON into Elasticsearch bulk requests via account names, allowing data forgery or service disruption in the Klever-Go indexer.
- 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-2026-82409?
CVE-2026-82409 is a high-severity code injection 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, indexer/common.go serializedDataForUpdateAccounts places the attacker-controlled acc.Name value into an Elasticsearch _bulk JSON and NDJSON request without escaping it. The SetAccountName transaction accepts valid UTF-8 account names containing quotes, backslashes, and newlines, and the resulting name is stored in consensus account state. When an indexer processes the account, those characters can break the JSON string, reject a bulk batch, or inject additional bulk actions that create, overwrite, or delete documents in indices writable by the indexer. The persistent state value is replayed by new or historical indexers, and direct access to the indexing host or Elasticsearch port is not required. This issue is fixed in version 1.7.20.
Weakness: CWE-116
Which versions are affected by CVE-2026-82409?
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-2026-82409?
Upgrade github.com/klever-io/klever-go to 1.7.20 or later.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-82409 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-82409 exists.
Sources
Also known as GHSA-7c7c-373r-gfjj, GO-2026-6585.