{"id":"CVE-2026-73568","summary":"py-libp2p: yamux connection DoS via oversized data frame","details":"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.","aliases":["GHSA-hmj8-5xmh-5573"],"modified":"2026-08-15T11:45:15.834919179Z","published":"2026-08-13T17:43:26.065Z","database_specific":{"cwe_ids":["CWE-400"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/73xxx/CVE-2026-73568.json","cna_assigner":"GitHub_M"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/73xxx/CVE-2026-73568.json"},{"type":"ADVISORY","url":"https://github.com/libp2p/py-libp2p/security/advisories/GHSA-hmj8-5xmh-5573"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-73568"},{"type":"FIX","url":"https://github.com/libp2p/py-libp2p/commit/146ea87d1a20cc7dacf684ecf7c204543be04b37"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/libp2p/py-libp2p","events":[{"introduced":"0"},{"fixed":"146ea87d1a20cc7dacf684ecf7c204543be04b37"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"last_affected":"0.7.0"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["v0.6.0","v0.5.0","v0.4.0","v0.3.0","v0.2.10","v0.2.9","v0.2.8","v0.2.7","v0.2.6","v0.2.5","v0.2.4","v0.2.3","v0.2.2","v0.2.1","v0.2.0","v0.1.5","v0.1.4","v0.1.3","v0.1.2","v0.1.1","v0.1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-73568.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}