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TI-2026-51658 Aliases CVE-2026-73568GHSA-hmj8-5xmh-5573

py-libp2p: yamux connection DoS via oversized data frame

Priority HIGH 72CWE-400Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-400.

Summary

py-libp2p is the Python implementation of the libp2p networking stack. In 0.7.0 and earlier, the yamux handle_incoming() method in libp2p/stream_muxer/yamux/yamux.py reads an attacker-controlled 32-bit DATA frame length with read_exactly() before validating it against MAX_WINDOW_SIZE or checking whether stream_id exists. A peer that completes the standard Noise handshake can send a 12-byte frame declaring a 0xFFFFFFFF body and then withhold the body, causing the sequential yamux read loop used by the default new_host() configuration to block and preventing every stream on that connection from making progress. No fixed version is available as of this review.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00488 42nd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
libp2ppy-libp2pup to 0.7.0—No fix listedCNA
—libp2p (PyPI)up to 0.7.0—No fix listedGHSA-hmj8-5xmh-5573
  • py-libp2p Vendorlibp2p Affected up to 0.7.0 Fixed in — No fix listed CNA
  • libp2p (PyPI) Vendor— Affected up to 0.7.0 Fixed in — No fix listed GHSA-hmj8-5xmh-5573

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-73568
  2. 2026-10-03 Alias added: GHSA-hmj8-5xmh-5573

References

Other 3

  • TI-2026-60386 libp2p-rendezvous through 0.17.1 Denial of Service via Unbounded Registration TTL in Discovery Responses CVSS 4.0HIGH 8.7
  • TI-2026-58865 libp2p: PeerStore accepts attacker-signed PeerRecords for a victim peer ID and stores certified attacker addresses CVSS 3.1HIGH 8.2
  • TI-2026-44102 libp2p-quic: Remote panic via certificate expiry race during QUIC handshake CVSS 4.0HIGH 8.2
  • TI-2026-27587 libp2p-rust has unbounded rendezvous DISCOVER cookies enable remote memory exhaustion CVSS 3.1HIGH 8.2
  • TI-2026-58864 libp2p: Gossipsub StrictSign accepts attacker-signed messages as a victim RSA peer ID CVSS 3.1HIGH 7.5
  • TI-2026-53982 libp2p: Circuit relay v2 server reservation refresh leaks abort listeners and allows remote resource exhaustion CVSS 3.1HIGH 7.5
See all 26 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences