CVE-2026-31814

Yamux remote Panic via malformed WindowUpdate credit

HIGH
7.5
CVSS Score
Published: March 13, 2026 at 07:19 PM UTC
Updated: June 17, 2026 at 10:34 AM UTC
2 products affected across 2 vendorsYamuxRust Yamux

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Severity
HIGH7.5
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

0.13.0 ≤ v < 0.13.9
v < 0.13.9
Affected range stops below 0.13.9, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

x_refsource_CONFIRMExploitVendor Advisory
Source: cverecord
https://github.com/libp2p/rust-yamux/security/advisories/GHSA-4w32-2493-32g7

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-190

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