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CVE-2026-52878

Klever-Go: Unauthenticated nil-pointer DoS in P2P transaction validation can halt the chain

7.5 HighFix available

Klever-Go is the Go implementation of the Klever blockchain protocol. Versions 1.7.14 through 1.7.17 are vulnerable to a nil-pointer panic triggered by a protobuf Transaction whose embedded RawData sub-message is omitted. This omission causes RawData to decode to nil. Every transaction gossiped on the Klever-Go P2P network is decoded and validated synchronously inside the libp2p pubsub topic-validator callback, where txVersionChecker.CheckTxVersion dereferences tx.RawData.Version with no nil check. Because the libp2p pubsub callback, the underlying go-libp2p-pubsub validation worker, and Klever's own network/p2p layer install no recover(), the panic propagates and crashes the entire node process. The attacker payload is a 3-byte protobuf message; no validator key, stake, funds, or on-chain account is required, and delivery aimed at enough of the BLS validator set can halt block production, resulting in a chain halt. This issue has been fixed in version 1.7.18.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
Low
Privileges needed
None
User interaction
None

What an attacker can affect

Confidentiality
None
Integrity
None
Availability
High

Exploit likelihood

0.49%Up 0.4 points since Jun 12, 2026
90%50%10%1%

What each source reports

CVE List Score used 7.5

Klever-Go: Unauthenticated nil-pointer DoS in P2P transaction validation can halt the chain

Klever-Go is the Go implementation of the Klever blockchain protocol. Versions 1.7.14 through 1.7.17 are vulnerable to a nil-pointer panic triggered by a protobuf Transaction whose embedded RawData sub-message is omitted. This omission causes RawData to decode to nil. Every transaction gossiped on the Klever-Go P2P network is decoded and validated synchronously inside the libp2p pubsub topic-validator callback, where txVersionChecker.CheckTxVersion dereferences tx.RawData.Version with no nil check. Because the libp2p pubsub callback, the underlying go-libp2p-pubsub validation worker, and Klever's own network/p2p layer install no recover(), the panic propagates and crashes the entire node process. The attacker payload is a 3-byte protobuf message; no validator key, stake, funds, or on-chain account is required, and delivery aimed at enough of the BLS validator set can halt block production, resulting in a chain halt. This issue has been fixed in version 1.7.18.

Record
CVE-2026-52878
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness
CWE-476
Updated
2026-11-02
EUVDEUVD-2026-54718 7.5

Klever-Go is the Go implementation of the Klever blockchain protocol. Versions 1.7.14 through 1.7.17 are vulnerable to a nil-pointer panic triggered by a protobuf Transaction whose embedded RawData sub-message is omitted. This omission causes RawData to decode to nil. Every transaction gossiped on the Klever-Go P2P network is decoded and validated synchronously inside the libp2p pubsub topic-validator callback, where txVersionChecker.CheckTxVersion dereferences tx.RawData.Version with no nil check. Because the libp2p pubsub callback, the underlying go-libp2p-pubsub validation worker, and Klever's own network/p2p layer install no recover(), the panic propagates and crashes the entire node process. The attacker payload is a 3-byte protobuf message; no validator key, stake, funds, or on-chain account is required, and delivery aimed at enough of the BLS validator set can halt block production, resulting in a chain halt. This issue has been fixed in version 1.7.18.

Record
EUVD-2026-54718
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated
2026-11-02
GitHub AdvisoriesGHSA-rm5c-5x2p-48wr 7.5

Klever-Go KVM: Unauthenticated remote node crash (nil-pointer DoS) in klever-go P2P transaction interceptor (txVersionChecker nil RawData) - potential chain halt

Summary

Every transaction gossiped on the klever-go P2P network is decoded and validated synchronously inside the libp2p pubsub topic-validator callback. The validator txVersionChecker.CheckTxVersion dereferences tx.RawData.Version with no nil check. A protobuf Transaction whose embedded RawData sub-message is omitted decodes to RawData == nil, so validating it triggers a nil-pointer panic.

The libp2p pubsub callback, the underlying go-libp2p-pubsub validation worker, and klever's own network/p2p layer install no recover(), so the panic propagates and crashes the entire node process. The attacker payload is a 3-byte protobuf message; no validator key, stake, funds, or on-chain account is required. Aimed at enough of the BLS validator set, repeated delivery halts block production (chain halt).

Affected component

  • Root cause: core/versioning/txVersionChecker.go:22
  • Reached via: core/process/transaction/interceptedTransaction.go:203 (integrity) and :154 (CheckValidity)
  • Production tx-topic path: core/process/interceptors/multiDataInterceptor.go:171 and :223
  • Unprotected caller: network/p2p/libp2p/netMessenger.go pubsubCallback (no recover)
  • Topic wiring: core/process/factory/interceptorscontainer/baseInterceptorsContainerFactory.go (createOneTxInterceptor)

Details

Synchronous validation path, no recovery at any frame:

libp2p pubsubCallback                              network/p2p/libp2p/netMessenger.go  (no recover)
 -> MultiDataInterceptor.ProcessReceivedMessage    core/process/interceptors/multiDataInterceptor.go:171
   -> interceptedData(...)                          core/process/interceptors/multiDataInterceptor.go:223
     -> InterceptedTransaction.CheckValidity         core/process/transaction/interceptedTransaction.go:154
       -> integrity()                                core/process/transaction/interceptedTransaction.go:203
         -> txVersionChecker.CheckTxVersion(tx)      core/versioning/txVersionChecker.go:22   <-- nil deref

Root cause (core/versioning/txVersionChecker.go):

func (tvc *txVersionChecker) CheckTxVersion(tx *transaction.Transaction) error {
	if tx.RawData.Version < tvc.minTxVersion {   // tx.RawData is nil -> panic
		return process.ErrInvalidTransactionVersion
	}
	return nil
}

integrity() calls CheckTxVersion as its very first statement, before any RawData nil-check, and CheckValidity() runs before the whitelist / originator- election gate in the interceptor, so node-role and whitelist restrictions do not protect this path.

Preconditions

  • Attacker runs an ordinary libp2p peer reachable to the target via normal peering / kad-dht discovery on the transactions gossip topic.
  • Production runs with withMessageSigning = true, which only requires the gossip message to be signed by the attacker's OWN libp2p peer key (a self-generated identity; NOT a validator key, NOT funded, NOT authorized).
  • No special config or feature flag; the tx interceptor is built unconditionally and subscribes to transactions on every node.

Impact

  • Deterministic, immediate crash of any targeted node (validator, sentry, or observer) from a single ~3-byte message.
  • Gossipsub validates before relaying, so the victim does not forward the crashing message; the attacker delivers it directly to each target (one tiny message/node).
  • With auto-restart (systemd), re-sending sustains the outage.
  • Directed at > 1/3 of the BLS validator set, this prevents consensus and halts the chain.
  • NOTE: the HTTP POST /transaction/send path is NOT crash-exploitable - the REST server uses gin.Default() (Recovery middleware) and returns HTTP 500. The exploitable vector is the P2P interceptor.

Exploit cost / attack complexity

  • Cost: negligible (one self-signed libp2p peer; 3-byte payload; no gas/capital).
  • Complexity: LOW. Unauthenticated, remote, deterministic.

PoC-Source

Scenario

  • Build the malicious transaction as it appears…
Record
GHSA-rm5c-5x2p-48wr
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness
CWE-476
Updated
2026-11-02
NVD 7.5

Klever-Go is the Go implementation of the Klever blockchain protocol. Versions 1.7.14 through 1.7.17 are vulnerable to a nil-pointer panic triggered by a protobuf Transaction whose embedded RawData sub-message is omitted. This omission causes RawData to decode to nil. Every transaction gossiped on the Klever-Go P2P network is decoded and validated synchronously inside the libp2p pubsub topic-validator callback, where txVersionChecker.CheckTxVersion dereferences tx.RawData.Version with no nil check. Because the libp2p pubsub callback, the underlying go-libp2p-pubsub validation worker, and Klever's own network/p2p layer install no recover(), the panic propagates and crashes the entire node process. The attacker payload is a 3-byte protobuf message; no validator key, stake, funds, or on-chain account is required, and delivery aimed at enough of the BLS validator set can halt block production, resulting in a chain halt. This issue has been fixed in version 1.7.18.

Record
CVE-2026-52878
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness
CWE-476
Updated
2026-11-02
OSV 7.5

Klever-Go: Unauthenticated nil-pointer DoS in P2P transaction validation can halt the chain

Klever-Go is the Go implementation of the Klever blockchain protocol. Versions 1.7.14 through 1.7.17 are vulnerable to a nil-pointer panic triggered by a protobuf Transaction whose embedded RawData sub-message is omitted. This omission causes RawData to decode to nil. Every transaction gossiped on the Klever-Go P2P network is decoded and validated synchronously inside the libp2p pubsub topic-validator callback, where txVersionChecker.CheckTxVersion dereferences tx.RawData.Version with no nil check. Because the libp2p pubsub callback, the underlying go-libp2p-pubsub validation worker, and Klever's own network/p2p layer install no recover(), the panic propagates and crashes the entire node process. The attacker payload is a 3-byte protobuf message; no validator key, stake, funds, or on-chain account is required, and delivery aimed at enough of the BLS validator set can halt block production, resulting in a chain halt. This issue has been fixed in version 1.7.18.

Record
CVE-2026-52878
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness
CWE-476
Updated
2026-11-02
OSVGHSA-rm5c-5x2p-48wr 7.5

Klever-Go KVM: Unauthenticated remote node crash (nil-pointer DoS) in klever-go P2P transaction interceptor (txVersionChecker nil RawData) - potential chain halt

Summary

Every transaction gossiped on the klever-go P2P network is decoded and validated synchronously inside the libp2p pubsub topic-validator callback. The validator txVersionChecker.CheckTxVersion dereferences tx.RawData.Version with no nil check. A protobuf Transaction whose embedded RawData sub-message is omitted decodes to RawData == nil, so validating it triggers a nil-pointer panic.

The libp2p pubsub callback, the underlying go-libp2p-pubsub validation worker, and klever's own network/p2p layer install no recover(), so the panic propagates and crashes the entire node process. The attacker payload is a 3-byte protobuf message; no validator key, stake, funds, or on-chain account is required. Aimed at enough of the BLS validator set, repeated delivery halts block production (chain halt).

Affected component

  • Root cause: core/versioning/txVersionChecker.go:22
  • Reached via: core/process/transaction/interceptedTransaction.go:203 (integrity) and :154 (CheckValidity)
  • Production tx-topic path: core/process/interceptors/multiDataInterceptor.go:171 and :223
  • Unprotected caller: network/p2p/libp2p/netMessenger.go pubsubCallback (no recover)
  • Topic wiring: core/process/factory/interceptorscontainer/baseInterceptorsContainerFactory.go (createOneTxInterceptor)

Details

Synchronous validation path, no recovery at any frame:

libp2p pubsubCallback                              network/p2p/libp2p/netMessenger.go  (no recover)
 -> MultiDataInterceptor.ProcessReceivedMessage    core/process/interceptors/multiDataInterceptor.go:171
   -> interceptedData(...)                          core/process/interceptors/multiDataInterceptor.go:223
     -> InterceptedTransaction.CheckValidity         core/process/transaction/interceptedTransaction.go:154
       -> integrity()                                core/process/transaction/interceptedTransaction.go:203
         -> txVersionChecker.CheckTxVersion(tx)      core/versioning/txVersionChecker.go:22   <-- nil deref

Root cause (core/versioning/txVersionChecker.go):

func (tvc *txVersionChecker) CheckTxVersion(tx *transaction.Transaction) error {
	if tx.RawData.Version < tvc.minTxVersion {   // tx.RawData is nil -> panic
		return process.ErrInvalidTransactionVersion
	}
	return nil
}

integrity() calls CheckTxVersion as its very first statement, before any RawData nil-check, and CheckValidity() runs before the whitelist / originator- election gate in the interceptor, so node-role and whitelist restrictions do not protect this path.

Preconditions

  • Attacker runs an ordinary libp2p peer reachable to the target via normal peering / kad-dht discovery on the transactions gossip topic.
  • Production runs with withMessageSigning = true, which only requires the gossip message to be signed by the attacker's OWN libp2p peer key (a self-generated identity; NOT a validator key, NOT funded, NOT authorized).
  • No special config or feature flag; the tx interceptor is built unconditionally and subscribes to transactions on every node.

Impact

  • Deterministic, immediate crash of any targeted node (validator, sentry, or observer) from a single ~3-byte message.
  • Gossipsub validates before relaying, so the victim does not forward the crashing message; the attacker delivers it directly to each target (one tiny message/node).
  • With auto-restart (systemd), re-sending sustains the outage.
  • Directed at > 1/3 of the BLS validator set, this prevents consensus and halts the chain.
  • NOTE: the HTTP POST /transaction/send path is NOT crash-exploitable - the REST server uses gin.Default() (Recovery middleware) and returns HTTP 500. The exploitable vector is the P2P interceptor.

Exploit cost / attack complexity

  • Cost: negligible (one self-signed libp2p peer; 3-byte payload; no gas/capital).
  • Complexity: LOW. Unauthenticated, remote, deterministic.

PoC-Source

Scenario

  • Build the malicious transaction as it appears…
Record
GHSA-rm5c-5x2p-48wr
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness
CWE-476
Updated
2026-11-02
OSVGO-2026-5628 No score

Klever-Go KVM: Unauthenticated remote node crash (nil-pointer DoS) in klever-go P2P transaction interceptor (txVersionChecker nil RawData) - potential chain halt in github.com/klever-io/klever-go

Klever-Go KVM: Unauthenticated remote node crash (nil-pointer DoS) in klever-go P2P transaction interceptor (txVersionChecker nil RawData) - potential chain halt in github.com/klever-io/klever-go

Record
GO-2026-5628
Updated
2026-11-02
OSVopenSUSE-SU-2026:21483-1 No score

Security update for govulncheck-vulndb

This update for govulncheck-vulndb fixes the following issues:

  • Update to version 0.0.20260723T184607 2026-07-23T18:46:07Z (jsc#PED-11136).

Go CVE Numbering Authority IDs added or updated with aliases:

  • GO-2026-4730 CVE-2026-33022 GHSA-cv4x-93xx-wgfj
  • GO-2026-4761 CVE-2026-33211 GHSA-j5q5-j9gm-2w5c
  • GO-2026-5102 CVE-2026-45021 GHSA-3vcp-chfh-f6r2
  • GO-2026-5272 CVE-2026-40938 GHSA-94jr-7pqp-xhcq
  • GO-2026-5486 CVE-2026-40924 GHSA-m2cx-gpqf-qf74
  • GO-2026-5542 CVE-2026-40090 GHSA-pj97-4p9w-gx3q
  • GO-2026-5630 CVE-2026-25542 GHSA-rmx9-2pp3-xhcr
  • GO-2026-5643 CVE-2026-40923 GHSA-rx35-6rhx-7858
  • GO-2026-5675 CVE-2026-41492 GHSA-vvf7-6rmr-m29q
  • GO-2026-5711 CVE-2026-40161 GHSA-wjxp-xrpv-xpff
  • GO-2026-5746 CVE-2026-41567 GHSA-x86f-5xw2-fm2r
  • GO-2026-5749 CVE-2026-41328 GHSA-x92x-px7w-4gx4
  • GO-2026-5837 CVE-2026-44840 GHSA-q2m9-6jp9-c6mc
  • GO-2026-5929 CVE-2026-44342 GHSA-26v7-h57m-gh9m
  • GO-2026-5930 CVE-2026-33655 GHSA-6qcr-qxgr-m7fv
  • GO-2026-5933 GHSA-3g4q-2f67-2gvh
  • GO-2026-5934 GHSA-59qp-cfj3-rp64
  • GO-2026-5935 GHSA-7856-g3gv-9wq8
  • GO-2026-5936 CVE-2026-53552 GHSA-26rh-24rg-j3vv
  • GO-2026-5937 CVE-2026-53508 GHSA-2jcc-mxv7-p3f9
  • GO-2026-5938 CVE-2026-53553 GHSA-4g5x-hcwm-82jw
  • GO-2026-5939 CVE-2026-10517 GHSA-698x-9w2p-7vvp
  • GO-2026-5940 CVE-2026-53572 GHSA-6w3m-4hhp-775q
  • GO-2026-5941 CVE-2026-53487 GHSA-gvhc-wv3v-7pf8
  • GO-2026-5942 CVE-2026-46600
  • GO-2026-5944 CVE-2026-50197 GHSA-659f-rgp5-w4wf
  • GO-2026-5945 CVE-2026-6815 GHSA-rmxx-v9rj-vpvg
  • GO-2026-5946 CVE-2026-52831 GHSA-v5px-423j-pf7p
  • GO-2026-5947 CVE-2026-53649 GHSA-xqhv-chqm-fhcc
  • GO-2026-5948 CVE-2026-50554 GHSA-588f-fvcv-xhvf
  • GO-2026-5949 CVE-2026-50553 GHSA-rqrh-8wpv-x7hh
  • GO-2026-5950 CVE-2026-53602 GHSA-339v-266x-79xr
  • GO-2026-5951 CVE-2026-10219 GHSA-6jm8-4fhr-5w64
  • GO-2026-5952 CVE-2026-49834 GHSA-9vcr-p3rj-q5q6
  • GO-2026-5953 CVE-2026-9094 GHSA-c9w5-qp6m-m395
  • GO-2026-5956 CVE-2026-55252 GHSA-h5g6-xmh4-hc37
  • GO-2026-5957 CVE-2026-54158 GHSA-5xfx-xj4h-5p7r
  • GO-2026-5958 CVE-2026-54068 GHSA-gcm7-57gf-953c
  • GO-2026-5959 CVE-2026-54072 GHSA-h29v-hj44-q8cv
  • GO-2026-5961 CVE-2026-54069 GHSA-hvr9-72v2-fff3
  • GO-2026-5962 CVE-2026-54088 GHSA-m93h-4hw7-5qcm
  • GO-2026-5963 CVE-2026-54067 GHSA-mvjr-vv3c-w4qv
  • GO-2026-5964 CVE-2026-54066 GHSA-p4m3-mgmm-c664
  • GO-2026-5965 CVE-2026-54070 GHSA-w7cg-whh7-xp28
  • GO-2026-5966 CVE-2026-54089 GHSA-xqp3-jq6g-x3qm
  • GO-2026-5967 CVE-2026-50551 GHSA-56mp-4f3v-fgj2
  • GO-2026-5968 CVE-2026-54174 GHSA-fpg8-7664-jc5q
  • GO-2026-5969 GHSA-g936-7jqj-mwv8
  • GO-2026-5970 CVE-2026-56852
  • GO-2026-5973 CVE-2026-54250 GHSA-jxr7-mqhw-9p98
  • GO-2026-5974 CVE-2026-44300 GHSA-wmj8-9953-vff5
  • GO-2026-5975 CVE-2026-50018 GHSA-42j2-w334-qxw7
  • GO-2026-5976 CVE-2026-50141 GHSA-g7mm-9vx7-jm7h
  • GO-2026-5977 CVE-2026-50013 GHSA-qrh4-p6v4-mrfg
  • GO-2026-5978 CVE-2026-50125 GHSA-qw5r-ppcg-f8rj
  • GO-2026-5979 CVE-2026-50006 GHSA-xrcf-6jh3-ggvx
  • GO-2026-5980 CVE-2026-50158 GHSA-2c7f-fxww-6w6c
  • GO-2026-5981 GHSA-mqxv-9rm6-w8qc
  • GO-2026-5982 GHSA-pqg7-v6wh-3pfp
  • GO-2026-5984 CVE-2026-53604 GHSA-2p2f-px33-4vv5
  • GO-2026-5985 GHSA-7rx3-5wx3-5v76
  • GO-2026-5986 CVE-2026-61699 GHSA-cm26-5974-52h8
  • GO-2026-5987 CVE-2026-55513 GHSA-g4x6-jcvr-9m3g
  • GO-2026-5988 CVE-2026-54628 GHSA-hwrq-8wxh-q4xv
  • GO-2026-5989 CVE-2026-55512 GHSA-m3cx-mwpg-32jg
  • GO-2026-5990 CVE-2026-54629 GHSA-mf78-3rpf-r784
  • GO-2026-5991 CVE-2026-53603 GHSA-q4vm-pq3q-8wgq
  • GO-2026-5992 CVE-2026-61549 GHSA-qf34-295c-26v8
  • GO-2026-5996 CVE-2026-54450 GHSA-pph6-vfjv-vpjw
  • GO-2026-5997 CVE-2026-54452 GHSA-xgch-x3mx-cm3c
  • GO-2026-5998 CVE-2026-54495 GHSA-398h-7f66-3h4p
  • GO-2026-5999 CVE-2026-10814 GHSA-jh6h-v6mp-h22v
  • GO-2026-6002 CVE-2026-58196 GHSA-pr64-jmmf-jp54
  • GO-2026-6003 CVE-2026-53714 GHSA-22xc-xg2r-9j7v
  • GO-2026-6004 CVE-2026-52833 GHSA-3v79-m2cg-89ww
  • GO-2026-6005 CVE-2026-53715 GHSA-8fv2-88gg-hm7q
  • GO-2026-6006 CVE-2026-53716 GHSA-cxpq-8v7q-cg56 *…
Record
openSUSE-SU-2026:21483-1
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
github.com/klever-io/klever-go
Go
 1.7.14 to 1.7.17
1.7.18
github.com/klever-io/klever-go
Go
 1.7.14 up to 1.7.18
1.7.18
govulncheck-vulndb
openSUSE:Leap 16.0
From an advisory covering 1734 CVEs
 before 0.0.20260723T184607-160000.1.1
0.0.20260723T184607-160000.1.1

History

History
RecordedChangedSources
affected, facts
first indexedCVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-52878 is a high vulnerability (CVSS 7.5) in Klever-io Klever-go, published June 5, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.49%, the 42nd percentile. Fixed in github.com/klever-io/klever-go 1.7.18.

References

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