CVE-2026-73568: libp2p py-libp2p Uncontrolled Resource Consumption
Vulnerability summary
CVE-2026-73568 is a high (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in libp2p py-libp2p. EPSS estimates a 0.49% chance of exploitation in the next 30 days, higher than 40.9% of scored vulnerabilities.
Timeline
- 13-08-2026PublishedVulnerability first disclosed.
- 13-08-2026Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
3 scores · 3 sources · 1 version- OSV · PypiEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.49%
Chance of exploitation in the next 30 days
Percentile
41%
Versus all other CVEs
30-day change
+0.07 pp
From 0.41% on 21-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Libp2p1 product
- py-libp2p≤ 0.7.0
PyPI1 product
- libp2p≤ 0.7.0
2 vendors · 2 products
References
6 links- github.com/libp2p/py-libp2pPACKAGE
- pypi.org/project/libp2pPACKAGE
