What is CVE-2026-31814?

CVE-2026-31814 is a high-severity vulnerability in Libp2p Rust-Yamux, classified under Integer Overflow or Wraparound. CVSS score: 7.5/10. Published 2026-03-13.

How severe is CVE-2026-31814?

High severity. CVSS v3 base score is 7.5 out of 10.

Integer overflow in Libp2p Rust-Yamux

CVE-2026-31814

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.

Vulnerability class: Integer Overflow

EPSS: 0.005 (37.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Libp2p Rust-yamux — versions >= 0.13.0, < 0.13.9
Protocol Yamux

Weakness classification (CWE)

CWE-190 — Integer Overflow or Wraparound

References

security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)

Frequently asked questions

What is CVE-2026-31814?: CVE-2026-31814 is a high-severity vulnerability in Libp2p Rust-Yamux, classified under Integer Overflow or Wraparound. CVSS score: 7.5/10. Published 2026-03-13.
How severe is CVE-2026-31814?: High severity. CVSS v3 base score is 7.5 out of 10.