Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Versions of the PyPI package libp2p up to and including 0.7.0 are affected by a denial-of-service flaw in its yamux stream multiplexer. The multiplexer reads the body of an incoming DATA frame without checking its declared length against the receive window, so a peer that completes the standard handshake can send one small frame that blocks the connection's read loop and stops all streams on it. No fixed version is listed, and the source gives no workaround.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 7.5 | High | 3.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0049, the 42nd percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:39 UTC First seen by agentprime
- 31 Oct 2026, 14:39 UTC Confirmed by OSV