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CVE-2026-49866

libp2p: CPU DoS via oversized IHAVE and IWANT control message arrays

Published: Jul 8, 2026Updated: Jul 10, 2026 Sources: CVE List NVDCWE-770
7.5HIGH
NVD MITRE
EPSS Score
0.4%
Top 63.8%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available
Self-Check
Not available

Description

libp2p is a JavaScript Implementation of libp2p networking stack. Prior to 16.0.0, @libp2p/gossipsub defaultDecodeRpcLimits set maxIhaveMessageIDs and maxIwantMessageIDs to Infinity, allowing oversized IHAVE and IWANT control message arrays in message/decodeRpc.ts and gossipsub.ts to synchronously iterate roughly 180,000 message IDs per 4 MB frame and block the Node.js event loop. This issue is fixed in version 16.0.0.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
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Weaknesses

CWE-770

Affected Products

libp2p
oss-projectaka rust-libp2p, go-libp2p, rust-yamux
js-libp2pLibrary
OSS Libraries / generic-library

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique
Impact
View detailed technique mapping

References

https://github.com/libp2p/js-libp2p/security/advisories/GHSA-cwc9-cp4j-mcvv
github.com
https://github.com/libp2p/js-libp2p/pull/3520
github.com
https://github.com/libp2p/js-libp2p/commit/773dd80ded24dbd6b19e675c89fd2f3b45f2d899
github.com
and 1 more references View all →

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