High severity · published Mar 13, 2026
CVE-2026-31814
Yamux remote Panic via malformed WindowUpdate credit
7.5
CVSS
0.5%
EPSS
No
On KEV
Description
Yamux is a stream multiplexer over reliable, ordered connections such as TCP/IP. From 0.13.0 to before 0.13.9, 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. This vulnerability is fixed in 0.13.9.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 41% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RU
rust-yamux · libp2p
>= 0.13.0, < 0.13.9 · source: vendor
YA
Yamux · Protocol
0.13.0 before 0.13.9 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-31814
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-31814
Exploit
https://github.com/libp2p/rust-yamux/security/advisories/GHSA-4w32-2493-32g7
More from rust-yamux
7.5
CVE-2026-32314
Yamux remote Panic via malformed Data frame with SYN set and len = 262145