What’s Vulnerable › Vulnerabilities

CVE-2026-77384: libp2p: Circuit relay v2 server reservation refresh leaks abort listeners and allows remote resource exhaustion

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-24 · updated 2026-10-12
• Weakness: CWE-400

Description

libp2p is a JavaScript implementation of the libp2p networking stack. Prior to version 4.2.9, the reservation refresh path in reservation-store.ts reuses the same retimeableSignal but unconditionally registers another abort listener on every refresh. As a result, a remote peer can repeatedly send valid RESERVE requests for the same reservation, causing unbounded listener and closure growth in @libp2p/circuit-relay-v2 relay servers and leading to denial of service. This issue is fixed in version 4.2.9.

Affected products

• libp2p js-libp2p: from 2.1.5, < 4.2.9

References

• https://github.com/libp2p/js-libp2p/commit/4bb8fbe8d3f3590e4af51a1f5f7de56fffa5804d
• https://github.com/libp2p/js-libp2p/releases/tag/circuit-relay-v2-v4.2.9
• https://github.com/libp2p/js-libp2p/security/advisories/GHSA-x787-gh7p-hmq7
• https://github.com/libp2p/js-libp2p/security/advisories/GHSA-x787-gh7p-hmq7

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