CVE-2026-86040 (GCVE-0-2026-86040)
Vulnerability from cvelistv5 – Published: 2026-09-17 15:20 – Updated: 2026-09-17 19:19
VLAI
EPSS
VEX
Title
libp2p: Unbounded RPC decode + synchronous subscription processing in @libp2p/floodsub allows unauthenticated DoS
Summary
libp2p is a JavaScript implementation of the libp2p networking stack. Prior to 11.0.26, @libp2p/floodsub accepts unauthenticated RPC frames on /floodsub/1.0.0 through PeerStreams.attachInboundStream in packages/floodsub/src/peer-streams.ts without protobuf element limits, then processRpc and processRpcSubOpt in packages/floodsub/src/floodsub.ts synchronously process the subscriptions array without a per-frame cap. A single bounded-size frame can decode into millions of empty subscription entries that block the event loop, while hundreds of thousands of unique-topic SUBSCRIBE entries allocate PeerSet objects in this.topics that are not removed after peer removal or stop. Empty entries cause CPU exhaustion but do not grow this.topics; persistent memory growth requires unique topics. The subscription path bypasses message signature validation and the message-only processing queue, allowing a remote peer to cause sustained CPU denial of service, memory exhaustion, out-of-memory termination, and node unavailability. The issue is fixed in version 11.0.26.
Severity
7.5 (High)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-17 17:06 UTC
CWE
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/libp2p/js-libp2p/security/advi… | x_refsource_CONFIRM |
| https://github.com/libp2p/js-libp2p/pull/3568 | x_refsource_MISC |
| https://github.com/libp2p/js-libp2p/commit/fb9e8a… | x_refsource_MISC |
| https://github.com/libp2p/js-libp2p/releases/tag/… | x_refsource_MISC |
Impacted products
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Sightings
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Vulnerability timeline
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Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
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