GHSA-4w32-2493-32g7
Yamux vulnerable to remote Panic via malformed WindowUpdate credit
Packages
Details
As written in the advisory (Markdown source, shown as plain text).
### Sumary
The Rust implementation of Yamux accepts `WindowUpdate` credit values from the remote peer and applies them to per-stream send-window state.
A specially crafted `WindowUpdate` can cause arithmetic overflow in send-window accounting, which triggers a panic in the connection state machine. This is remotely reachable over a normal network connection and does not require authentication.
#### Attack Scenario
An attacker that can establish a Yamux session with a target node can crash the target by sending two validly encoded Yamux frames:
1. Open a stream (e.g. DATA + SYN) so the stream exists with initial send-window state (`DEFAULT_CREDIT`).
2. Send a WindowUpdate on that stream with a very large credit value (e.g. 0xFFFF_0000) such that adding credit to the current send-window overflows u32.
### Impact
Remote unauthenticated denial of service.
An attacker can repeatedly trigger panics by reconnecting and replaying the crafted frame sequence.
### Patches
Users should upgrade to `yamux` `v0.13.9`
This vulnerability was originally submitted by @revofusion to the Ethereum Foundation bug bounty program
References
External links from the advisory. They lead to third-party sites.
- https://github.com/libp2p/rust-yamux/security/advisories/GHSA-4w32-2493-32g7
- https://nvd.nist.gov/vuln/detail/CVE-2026-31814
- https://github.com/libp2p/rust-yamux/pull/221
- https://github.com/libp2p/rust-yamux/commit/b1aae09d60c0bd6a5915a5448f4e8cbc5174db53
- https://github.com/libp2p/rust-yamux
- https://github.com/libp2p/rust-yamux/releases/tag/yamux-v0.13.9