CVE-2026-32314

HighPublic PoC

Published: 16 March 2026

Published

16 March 2026

Modified

19 March 2026

KEV Added

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Patch

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CVSS Score 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Score 0.0008 24.1th percentile

Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-32314 is a high-severity Uncaught Exception (CWE-248) vulnerability in Protocol Yamux. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 24.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

Threat & Defense at a Glance

What attackers do: exploitation maps to Application or System Exploitation (T1499.004).

Threat & Defense Details

Likely Mitigating ControlsAI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SC-24 Fail in Known State

addresses: CWE-248

Prevents abrupt termination from uncaught exceptions by requiring a defined, preserved-state failure mode.

SI-17 Fail-safe Procedures

addresses: CWE-248

Requires pre-defined safe responses for uncaught exceptions so they do not result in undefined or insecure program termination.

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact

Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.

attack.mitre.org →

Why these techniques?

Remote unauthenticated crash via crafted Yamux Data frame with oversized body directly enables application exploitation resulting in endpoint DoS (T1499.004).

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

Yamux is a stream multiplexer over reliable, ordered connections such as TCP/IP. Prior to 0.13.10, the Rust implementation of Yamux can panic when processing a crafted inbound Data frame that sets SYN and uses a body length greater than DEFAULT_CREDIT…

(e.g. 262145). On the first packet of a new inbound stream, stream state is created and a receiver is queued before oversized-body validation completes. When validation fails, the temporary stream is dropped and cleanup may call remove(...).expect("stream not found"), triggering a panic in the connection state machine. This is remotely reachable over a normal Yamux session and does not require authentication. This vulnerability is fixed in 0.13.10.

Deeper analysisAI

CVE-2026-32314 is a denial-of-service vulnerability in the Rust implementation of Yamux, a stream multiplexer over reliable, ordered connections such as TCP/IP. The issue affects versions prior to 0.13.10 and stems from a panic triggered when processing a crafted inbound Data frame that sets the SYN flag and specifies a body length greater than the DEFAULT_CREDIT value (e.g., 262145). On the first packet of a new inbound stream, the stream state is created and a receiver is queued before oversized-body validation completes; when validation fails, dropping the temporary stream leads to a cleanup call that invokes remove(...).expect("stream not found"), causing a panic in the connection state machine.

Any remote attacker can exploit this vulnerability over a normal Yamux session without authentication by sending the malicious frame, resulting in a crash of the affected Yamux connection. The CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) reflects its network accessibility, low attack complexity, lack of privileges or user interaction requirements, and high impact on availability due to the unhandled exception (CWE-248).

The vulnerability is fixed in Yamux version 0.13.10, as detailed in the GitHub Security Advisory at https://github.com/libp2p/rust-yamux/security/advisories/GHSA-vxx9-2994-q338. Security practitioners should upgrade to the patched version to mitigate the risk of remote denial-of-service attacks.