# CVE-2026-49343: Klever-io Klever-Go throttler slot leak in trie account-data sync

Source: https://junglewise.ai/threats/cve-2026-49343-klever-io-klever-go-throttler-slot-leak-in-trie-account-data-sync  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-07. Updated: 2026-06-05  
License: CC BY 4.0 with a link back

CVE-2026-49343 · Severity: medium · CVSS 5.9 · Published 2026-08-07

Klever-Go is a blockchain infrastructure component. A flaw in how it manages internal processing tasks during data synchronization allows an attacker to trigger repeated failures that permanently consume available task slots. This can lead to a denial-of-service condition where the system is unable to sync state or complete its startup process, effectively knocking the node offline.

Technologies: [github.com/klever-io/klever-go (Go)](https://junglewise.ai/threats/technologies/github-com-klever-io-klever-go). Vendors: [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2026-49343 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-49343 being exploited in the wild.

**How severe is CVE-2026-49343?** Medium severity, with a CVSS score of 5.9, published 7 August 2026.

**Which products and versions are affected?** github.com/klever-io/klever-go (Go) < 1.7.18, SEMVER:introduced=0,fixed=1.7.18.

**Is there a fix for CVE-2026-49343?** Yes. github.com/klever-io/klever-go (Go): upgrade to 1.7.18 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-49343 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-49343?** Check whether you run github.com/klever-io/klever-go (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/klever-io/klever-go (Go): upgrade to 1.7.18 or later

  ```sh
  go get github.com/klever-io/klever-go@v1.7.18
  ```


## Technical details

A resource leak exists in the `syncDataTrie()` function within `userAccountsSyncer.go` and `kappAccountsSyncer.go`. The component calls `StartProcessing()` on a `NumGoRoutinesThrottler` but fails to call `EndProcessing()` on several error return paths, such as when `NewTrie`, `NewTrieSyncer`, or `StartSyncing` fail. Because the throttler uses a strict bounded counter, these leaked slots are never recovered. An attacker who can induce network timeouts or synchronization errors can exhaust the throttler's capacity, preventing further state synchronization and causing epoch bootstrap to fail. This was patched in version 1.7.18 by ensuring the throttler slot is released using a deferred call.

## Affected products

- klever-io klever-go < 1.7.18

## Identifiers

- CVE-2026-49343
- GHSA-fw38-pc54-jvx9
- GO-2026-5379

## Timeline

- 2026-05-20: other: Vulnerability observed on develop branch
- 2026-06-02: advisory: GitHub Advisory published
- 2026-06-05: disclosed: CVE-2026-49343 published

## References

- [https://api.github.com/users/maiiquynhh](https://api.github.com/users/maiiquynhh)
- [https://github.com/maiiquynhh](https://github.com/maiiquynhh)
- [https://api.github.com/users/maiiquynhh/gists%7B/gist_id%7D](https://api.github.com/users/maiiquynhh/gists%7B/gist_id%7D)
- [https://api.github.com/users/maiiquynhh/repos](https://api.github.com/users/maiiquynhh/repos)
- [https://avatars.githubusercontent.com/u/64117178?v=4](https://avatars.githubusercontent.com/u/64117178?v=4)
- [https://api.github.com/users/maiiquynhh/events%7B/privacy%7D](https://api.github.com/users/maiiquynhh/events%7B/privacy%7D)

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- [Klever-Go Elasticsearch injection via account name](https://junglewise.ai/threats/cve-2026-82409-klever-go-elasticsearch-injection-via-account-name)
- [Klever-Go BLS public key validation bypass in validator registration](https://junglewise.ai/threats/cve-2026-82407-klever-go-bls-public-key-validation-bypass-in-validator)
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