How severe is GHSA-9wh6-9hq7-9688?

No CVSS score has been assigned to GHSA-9wh6-9hq7-9688 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-9wh6-9hq7-9688?

GHSA-9wh6-9hq7-9688 affects the following packages: github.com/klever-io/klever-go (Go). Ecosystems affected: Go.

How do I fix GHSA-9wh6-9hq7-9688?

Update github.com/klever-io/klever-go to 1.7.20 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9wh6-9hq7-9688 is resolved across your whole dependency graph.

How do I detect GHSA-9wh6-9hq7-9688 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/klever-io/klever-go, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-9wh6-9hq7-9688 if there is no patch (or I can't update yet)?

Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

Is GHSA-9wh6-9hq7-9688 actively exploited in the wild?

No public exploit code has been indexed for GHSA-9wh6-9hq7-9688 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-9wh6-9hq7-9688?

GHSA-9wh6-9hq7-9688 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 37th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-9wh6-9hq7-9688?

GHSA-9wh6-9hq7-9688 is classified as Improper Input Validation (CWE-20). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-9wh6-9hq7-9688 published, and has it been updated?

GHSA-9wh6-9hq7-9688 was published on September 23, 2026 and was last updated on October 1, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

Not in CISA KEV

Klever-Go: Validator registration accepts an unvalidated BLS public key → consensus liveness DoSGHSA-9wh6-9hq7-9688

Fix: klever-io/klever-go@11606a9

GHSA-9wh6-9hq7-9688 is a Improper Input Validation vulnerability in github.com/klever-io/klever-go. A fix is available for github.com/klever-io/klever-go — see the affected versions and patch details below.

Also known asCVE-2026-82407GO-2026-6586

Published

Sep 23, 2026

Updated

Oct 1, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 22, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.

Exploitation and automatability from CISA’s SSVC triage for GHSA-9wh6-9hq7-9688.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs37th percentile — riskier than 37% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

🐹github.com/klever-io/klever-go

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Location: core/kapp/validators/validators.go:201 (Register), (genesis/checking/nodesSetupChecker.go:73). core/consensus/slot/bls/subslotStartSlot.go:165 core/consensus/.../headerSignatureVerify.go:123 (Create(...)).

Description

Klever uses a BDN (Boneh-Drijvers-Neven) BLS multi-signature over BLS12-381 to finalize blocks (crypto/signing/mcl/multisig/bls.go, herumi/bls-go-binary). The library is initialized with only bls.Init(bls.BLS12_381) and no order-verification flags, so Deserialize does not enforce prime-order-subgroup membership subgroup safety relies on explicit IsValidOrder() calls in the wrappers.

Runtime validator registration (validators.Register) stores the submitted 96-byte BLSPublicKey via SetBLSPublicKey with no curve check, no subgroup check, and no proof-of-possession (CreateValidatorContract carries the key but no signature proving key ownership; grep confirms no proofOfPossession/VerifyProof/BLSSignature verification anywhere in core/kapp/validators/). CheckPublicKeyValid — which does IsValid && IsValidOrder && !IsZero — runs only at genesis, not on runtime registration/update.

POC

Attack: (1) stake the minimum to register a validator, submitting a 96-byte BLSPublicKey that is not a valid G2 point (arbitrary bytes). Registration succeeds. (2) Once the validator is eligible and selected into a consensus group, every in-group node including the honest leader (group[0]) calls MultiSigner().Reset(groupPubKeys, selfIndex) at slot start, which deserializes all group keys via PublicKeyFromByteArray → herumi Deserialize deterministically fails on the malformed key → SetSlotCanceled(true). The verify side (Create(consensusPubKeys)) fails identically. No block is produced for that round.

Impact

Every consensus round whose group contains the malformed-key validator is a missed slot. One eligible bad-key validator poisons roughly a groupSize / eligibleSet fraction of rounds → sustained liveness degradation. Where the consensus group equals the eligible set (small or early-stage networks), this is a full chain halt. Cost is the minimum validator stake, permissionless, and repeatable; no fork flag gates the missing validation.

Rated High (Byzantine liveness; Critical on small validator sets). The severity scales down to a fractional missed-slot / throughput-degradation attack on a large validator set where the bad validator is only occasionally in the active group.

Recommendation

Enforce CheckPublicKeyValid (curve + prime-order subgroup + non-zero) on the submitted BLS key at runtime validator registration and config-update, and ideally require a proof-of-possession (a BLS signature over the validator's own key/identity) at registration to prove key ownership and well-formedness. Gate the stricter validation behind an epoch fork flag for reprocessing consistency.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/klever-io/klever-go`	all versions	1.7.20`go get github.com/klever-io/klever-go@v1.7.20`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/klever-io/klever-go, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/klever-io/klever-go to 1.7.20 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9wh6-9hq7-9688 is resolved across your whole dependency graph.
Workarounds
Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

Frequently Asked Questions

**Location:** `core/kapp/validators/validators.go:201` (`Register`), (`genesis/checking/nodesSetupChecker.go:73`). `core/consensus/slot/bls/subslotStartSlot.go:165` `core/consensus/.../headerSignatureVerify.go:123` (`Create(...)`). ### Description Klever uses a BDN (Boneh-Drijvers-Neven) BLS multi-signature over BLS12-381 to finalize blocks (`crypto/signing/mcl/multisig/bls.go`, herumi/bls-go-binary). The library is initialized with only `bls.Init(bls.BLS12_381)` and no order-verification flags, so `Deserialize` does not enforce prime-order-subgroup membership subgroup safety relies on expl

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Klever-Go: Validator registration accepts an unvalidated BLS public key → consensus liveness DoSGHSA-9wh6-9hq7-9688

Exploitation Status

Proof-of-concept exploit code exists

EPSS Exploitation Probability

Real-World Exposure

Description

Description

POC

Impact

Recommendation

Affected Packages

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

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