Vulnerability · Published Sep 23, 2026 · Assigned by GitHub_M
CVE-2026-82406Klever-Go: Zombie-order theft: `Buy` missing `IsClaimed` guard in native marketplace
High 7.1
In plain English
A high-severity security flaw in klever-go from klever-io. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 38% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Klever-Go is the Go implementation of the Klever blockchain protocol. Prior to 1.7.20, the native marketplace function core/kapp/market/market.go Buy does not check IsClaimed before accepting a bid. A seller can use the Claim seller-accept branch to settle a resting-bid auction while leaving the claimed order loadable with a future EndTime and stale CurrentBid and CurrentBidder values. A later bidder can submit a higher bid, be debited, and cause the previous bidder to receive a refund even though the NFT has already been delivered. Because Claim and CancelOrder reject the later bidder when IsClaimed is true, the later bidder cannot obtain the NFT or recover the funds. This issue is fixed in version 1.7.20.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/klever-io/klever-go | 1.7.20 | GHSA-26r5-4mm2-px5c |
| Go | github.com/klever-io/klever-go | 1.7.20 | GO-2026-6584 |
Affected products (as reported)
Weakness: CWE-841 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
References
- https://github.com/klever-io/klever-go/security/advisories/GHSA-26r5-4mm2-px5c x_refsource_CONFIRM
- https://github.com/klever-io/klever-go/pull/16 x_refsource_MISC
- https://github.com/klever-io/klever-go/commit/063bb3ed98f9a84a4b1f7286680613a5fc3c91b2 x_refsource_MISC
- https://github.com/klever-io/klever-go/releases/tag/v1.7.20 x_refsource_MISC