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CVE-2026-52879

Klever-Go: Unbounded goroutine spawn on direct-message ingress enables peer-driven DoS

7.5 HighFix available

Klever-Go is the Go implementation of the Klever blockchain protocol. In versions 1.7.14 through 1.7.17, the direct-message ingress handler spawns a new goroutine for every incoming direct message before the processor-level antiflood layer makes any admission decision, with no semaphore, throttler, or bound on the number of concurrent in-flight spawns. Because the antiflood check runs inside the spawned goroutine rather than before it, a single connected peer can open a direct-send stream and send a stream of well-formed messages to force unbounded goroutine creation, where each goroutine allocates its own stack and holds a message reference until processing completes, adding scheduler and garbage-collection pressure faster than the runtime can drain it. This lets one peer degrade the node's availability and its ability to process legitimate traffic, resulting in a remotely triggerable denial of service. The issue is fixed in 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: Unbounded goroutine spawn on direct-message ingress enables peer-driven DoS

Klever-Go is the Go implementation of the Klever blockchain protocol. In versions 1.7.14 through 1.7.17, the direct-message ingress handler spawns a new goroutine for every incoming direct message before the processor-level antiflood layer makes any admission decision, with no semaphore, throttler, or bound on the number of concurrent in-flight spawns. Because the antiflood check runs inside the spawned goroutine rather than before it, a single connected peer can open a direct-send stream and send a stream of well-formed messages to force unbounded goroutine creation, where each goroutine allocates its own stack and holds a message reference until processing completes, adding scheduler and garbage-collection pressure faster than the runtime can drain it. This lets one peer degrade the node's availability and its ability to process legitimate traffic, resulting in a remotely triggerable denial of service. The issue is fixed in 1.7.18.

Record
CVE-2026-52879
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-400, CWE-770
Updated
2026-11-02
EUVDEUVD-2026-54720 7.5

Klever-Go is the Go implementation of the Klever blockchain protocol. In versions 1.7.14 through 1.7.17, the direct-message ingress handler spawns a new goroutine for every incoming direct message before the processor-level antiflood layer makes any admission decision, with no semaphore, throttler, or bound on the number of concurrent in-flight spawns. Because the antiflood check runs inside the spawned goroutine rather than before it, a single connected peer can open a direct-send stream and send a stream of well-formed messages to force unbounded goroutine creation, where each goroutine allocates its own stack and holds a message reference until processing completes, adding scheduler and garbage-collection pressure faster than the runtime can drain it. This lets one peer degrade the node's availability and its ability to process legitimate traffic, resulting in a remotely triggerable denial of service. The issue is fixed in 1.7.18.

Record
EUVD-2026-54720
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-hf2g-6j7h-98wg 7.5

klever-go: Unbounded goroutine spawn on direct-message ingress enables peer-driven DoS

Summary

networkMessenger.directMessageHandler in network/p2p/libp2p/netMessenger.go spawns a fresh goroutine for every incoming direct message before the antiflood layer makes an admission decision. There is no semaphore, throttler, or bound on concurrent in-flight spawns.

A single connected libp2p peer can open a DirectSendID stream and send well-formed TopicMessage envelopes with varying sequence numbers. Each accepted direct message reaches directMessageHandler and triggers a fresh goroutine before processor.ProcessReceivedMessage runs. This allows unbounded goroutine growth and node availability degradation from one peer.

This remains present in the latest release v1.7.17: network/p2p/libp2p/netMessenger.go:1060 still spawns go func(msg p2p.MessageP2P) before processor.ProcessReceivedMessage. I also verified current develop commit 10bcfd50, where the same spawn remains at network/p2p/libp2p/netMessenger.go:1115.

This is distinct from GHSA-74m6-4hjp-7226 and GHSA-87m7-qffr-542v. Those advisories concern MultiDataInterceptor decompression/throttler behavior. This report concerns the libp2p direct-message ingress wrapper spawning an unbounded goroutine before processor-level antiflood/admission logic runs. A patch to Batch.Decompress or MultiDataInterceptor does not bound this direct-message goroutine spawn.

Details

The affected path is network/p2p/libp2p/netMessenger.go in directMessageHandler.

The direct-message path transforms and validates the message, looks up the topic processor, then immediately spawns a goroutine:

func (netMes *networkMessenger) directMessageHandler(message *pubsub.Message, fromConnectedPeer core.PeerID) error {
    var processor p2p.MessageProcessor

    topic := *message.Topic
    msg, err := netMes.transformAndCheckMessage(message, fromConnectedPeer, topic)
    if err != nil {
        return err
    }

    netMes.mutTopics.RLock()
    processor = netMes.processors[topic]
    netMes.mutTopics.RUnlock()

    if processor == nil {
        return fmt.Errorf("%w on directMessageHandler for topic %s", p2p.ErrNilValidator, topic)
    }

    go func(msg p2p.MessageP2P) {
        if check.IfNil(msg) {
            return
        }

        errProcess := processor.ProcessReceivedMessage(msg, fromConnectedPeer)
        // ...
    }(msg)

    return nil
}

The processor-level antiflood decision happens inside ProcessReceivedMessage, after the goroutine, its stack, and the cloned message reference already exist. That means antiflood can bound processing rate, but not goroutine creation rate.

The existing goRoutinesThrottler with capacity broadcastGoRoutines = 1000 is wired into outgoing broadcast paths such as BroadcastOnChannelBlocking, not this incoming direct-message path.

The parallel pubsub ingress path in the same file handles a comparable inbound message surface synchronously:

err = handler.ProcessReceivedMessage(msg, fromConnectedPeer)

So the direct-message path is asymmetric: same transform/check function, same ProcessReceivedMessage callee, but direct-message ingress adds an unbounded goroutine spawn.

Reachability:

  • directSender.go registers DirectSendID as a libp2p stream protocol.
  • directStreamHandler reads framed pubsub.Message envelopes from the stream.
  • directStreamHandler forwards each message to networkMessenger.directMessageHandler.
  • Any connected peer can send well-formed envelopes to registered topics.
  • The seenMessages cache keys on From + Seqno; Seqno is attacker-controlled in the envelope, so incrementing it bypasses dedupe.

PoC

GitHub Private Vulnerability Reporting does not appear to allow file attachments in this form, so I am including the reproduction command and captured output inline. I can provide the full Go test file immediately if useful.

The PoC is a Go test file intended to be placed under network/p2p/libp2p/ in a klever-go checkout. It exercises the real…

Record
GHSA-hf2g-6j7h-98wg
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-400, CWE-770
Updated
2026-11-02
NVD 7.5

Klever-Go is the Go implementation of the Klever blockchain protocol. In versions 1.7.14 through 1.7.17, the direct-message ingress handler spawns a new goroutine for every incoming direct message before the processor-level antiflood layer makes any admission decision, with no semaphore, throttler, or bound on the number of concurrent in-flight spawns. Because the antiflood check runs inside the spawned goroutine rather than before it, a single connected peer can open a direct-send stream and send a stream of well-formed messages to force unbounded goroutine creation, where each goroutine allocates its own stack and holds a message reference until processing completes, adding scheduler and garbage-collection pressure faster than the runtime can drain it. This lets one peer degrade the node's availability and its ability to process legitimate traffic, resulting in a remotely triggerable denial of service. The issue is fixed in 1.7.18.

Record
CVE-2026-52879
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-400, CWE-770
Updated
2026-11-02
OSV 7.5

Klever-Go: Unbounded goroutine spawn on direct-message ingress enables peer-driven DoS

Klever-Go is the Go implementation of the Klever blockchain protocol. In versions 1.7.14 through 1.7.17, the direct-message ingress handler spawns a new goroutine for every incoming direct message before the processor-level antiflood layer makes any admission decision, with no semaphore, throttler, or bound on the number of concurrent in-flight spawns. Because the antiflood check runs inside the spawned goroutine rather than before it, a single connected peer can open a direct-send stream and send a stream of well-formed messages to force unbounded goroutine creation, where each goroutine allocates its own stack and holds a message reference until processing completes, adding scheduler and garbage-collection pressure faster than the runtime can drain it. This lets one peer degrade the node's availability and its ability to process legitimate traffic, resulting in a remotely triggerable denial of service. The issue is fixed in 1.7.18.

Record
CVE-2026-52879
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-400, CWE-770
Updated
2026-11-02
OSVGHSA-hf2g-6j7h-98wg 7.5

klever-go: Unbounded goroutine spawn on direct-message ingress enables peer-driven DoS

Summary

networkMessenger.directMessageHandler in network/p2p/libp2p/netMessenger.go spawns a fresh goroutine for every incoming direct message before the antiflood layer makes an admission decision. There is no semaphore, throttler, or bound on concurrent in-flight spawns.

A single connected libp2p peer can open a DirectSendID stream and send well-formed TopicMessage envelopes with varying sequence numbers. Each accepted direct message reaches directMessageHandler and triggers a fresh goroutine before processor.ProcessReceivedMessage runs. This allows unbounded goroutine growth and node availability degradation from one peer.

This remains present in the latest release v1.7.17: network/p2p/libp2p/netMessenger.go:1060 still spawns go func(msg p2p.MessageP2P) before processor.ProcessReceivedMessage. I also verified current develop commit 10bcfd50, where the same spawn remains at network/p2p/libp2p/netMessenger.go:1115.

This is distinct from GHSA-74m6-4hjp-7226 and GHSA-87m7-qffr-542v. Those advisories concern MultiDataInterceptor decompression/throttler behavior. This report concerns the libp2p direct-message ingress wrapper spawning an unbounded goroutine before processor-level antiflood/admission logic runs. A patch to Batch.Decompress or MultiDataInterceptor does not bound this direct-message goroutine spawn.

Details

The affected path is network/p2p/libp2p/netMessenger.go in directMessageHandler.

The direct-message path transforms and validates the message, looks up the topic processor, then immediately spawns a goroutine:

func (netMes *networkMessenger) directMessageHandler(message *pubsub.Message, fromConnectedPeer core.PeerID) error {
    var processor p2p.MessageProcessor

    topic := *message.Topic
    msg, err := netMes.transformAndCheckMessage(message, fromConnectedPeer, topic)
    if err != nil {
        return err
    }

    netMes.mutTopics.RLock()
    processor = netMes.processors[topic]
    netMes.mutTopics.RUnlock()

    if processor == nil {
        return fmt.Errorf("%w on directMessageHandler for topic %s", p2p.ErrNilValidator, topic)
    }

    go func(msg p2p.MessageP2P) {
        if check.IfNil(msg) {
            return
        }

        errProcess := processor.ProcessReceivedMessage(msg, fromConnectedPeer)
        // ...
    }(msg)

    return nil
}

The processor-level antiflood decision happens inside ProcessReceivedMessage, after the goroutine, its stack, and the cloned message reference already exist. That means antiflood can bound processing rate, but not goroutine creation rate.

The existing goRoutinesThrottler with capacity broadcastGoRoutines = 1000 is wired into outgoing broadcast paths such as BroadcastOnChannelBlocking, not this incoming direct-message path.

The parallel pubsub ingress path in the same file handles a comparable inbound message surface synchronously:

err = handler.ProcessReceivedMessage(msg, fromConnectedPeer)

So the direct-message path is asymmetric: same transform/check function, same ProcessReceivedMessage callee, but direct-message ingress adds an unbounded goroutine spawn.

Reachability:

  • directSender.go registers DirectSendID as a libp2p stream protocol.
  • directStreamHandler reads framed pubsub.Message envelopes from the stream.
  • directStreamHandler forwards each message to networkMessenger.directMessageHandler.
  • Any connected peer can send well-formed envelopes to registered topics.
  • The seenMessages cache keys on From + Seqno; Seqno is attacker-controlled in the envelope, so incrementing it bypasses dedupe.

PoC

GitHub Private Vulnerability Reporting does not appear to allow file attachments in this form, so I am including the reproduction command and captured output inline. I can provide the full Go test file immediately if useful.

The PoC is a Go test file intended to be placed under network/p2p/libp2p/ in a klever-go checkout. It exercises the real…

Record
GHSA-hf2g-6j7h-98wg
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-400, CWE-770
Updated
2026-11-02
OSVGO-2026-5424 No score

klever-go: Unbounded goroutine spawn on direct-message ingress enables peer-driven DoS in github.com/klever-io/klever-go

klever-go: Unbounded goroutine spawn on direct-message ingress enables peer-driven DoS in github.com/klever-io/klever-go

Record
GO-2026-5424
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-2026-52879 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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