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. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

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

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-4w32-2493-32g7?

O3 pinpoints whether GHSA-4w32-2493-32g7 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

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 37th 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

GHSA-4w32-2493-32g7

Yamux vulnerable to remote Panic via malformed WindowUpdate credit

Also known asCVE-2026-31814

Published

Mar 13, 2026

Updated

Mar 16, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk37th percentile+0.43%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

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

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for yamux. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
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
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-4w32-2493-32g7 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-4w32-2493-32g7. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

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

Is GHSA-4w32-2493-32g7 in your dependencies?

O3 detects GHSA-4w32-2493-32g7 across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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