How severe is GHSA-4w32-2493-32g7?

No CVSS score has been assigned to GHSA-4w32-2493-32g7 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-4w32-2493-32g7?

GHSA-4w32-2493-32g7 affects the following packages: yamux (crates.io). Ecosystems affected: crates.io.

How do I fix GHSA-4w32-2493-32g7?

Update yamux to 0.13.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4w32-2493-32g7 is resolved across your whole dependency graph.

How do I detect GHSA-4w32-2493-32g7 in my crates.io dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for yamux, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-4w32-2493-32g7 if there is no patch (or I can't update yet)?

Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process.

Is GHSA-4w32-2493-32g7 actively exploited in the wild?

No public exploit code has been indexed for GHSA-4w32-2493-32g7 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-4w32-2493-32g7?

GHSA-4w32-2493-32g7 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 42th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-4w32-2493-32g7?

GHSA-4w32-2493-32g7 is classified as CWE-190 (CWE-190). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-4w32-2493-32g7 published, and has it been updated?

GHSA-4w32-2493-32g7 was published on March 13, 2026 and was last updated on March 16, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🦀 crates.io

Not in CISA KEV

Yamux vulnerable to remote Panic via malformed WindowUpdate creditGHSA-4w32-2493-32g7

Fix: libp2p/rust-yamux#221

GHSA-4w32-2493-32g7 is a CWE-190 vulnerability in yamux. A fix is available for yamux — see the affected versions and patch details below.

Also known asCVE-2026-31814

Published

Mar 13, 2026

Updated

Mar 16, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 5, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-4w32-2493-32g7.

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs42th percentile — riskier than 42% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

🦀yamux

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.

Description

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:

Open a stream (e.g. DATA + SYN) so the stream exists with initial send-window state (DEFAULT_CREDIT).
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

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🦀crates.io	`yamux`	≥ 0.13.0&&< 0.13.9	0.13.9`cargo update -p yamux --precise 0.13.9`

Affected Products

1 product · 1 configurations

Application

yamuxprotocol

≥ 0.13.0 && < 0.13.9

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for yamux, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update yamux to 0.13.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4w32-2493-32g7 is resolved across your whole dependency graph.
Workarounds
Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process.

Frequently Asked Questions

### 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 stre

O3 Security · Impact-Aware SCA

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