How severe is GHSA-vxx9-2994-q338?

No CVSS score has been assigned to GHSA-vxx9-2994-q338 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-vxx9-2994-q338?

GHSA-vxx9-2994-q338 affects the following packages: yamux (crates.io). Ecosystems affected: crates.io.

How do I fix GHSA-vxx9-2994-q338?

Update yamux to 0.13.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-vxx9-2994-q338 is resolved across your whole dependency graph.

How do I detect GHSA-vxx9-2994-q338 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-vxx9-2994-q338 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-vxx9-2994-q338?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-vxx9-2994-q338 can be triaged on real exposure rather than presence alone.

Is GHSA-vxx9-2994-q338 actively exploited in the wild?

No public exploit code has been indexed for GHSA-vxx9-2994-q338 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-vxx9-2994-q338?

GHSA-vxx9-2994-q338 has an EPSS (Exploit Prediction Scoring System) score of 0.6%, placing it in the 45th 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-vxx9-2994-q338?

GHSA-vxx9-2994-q338 is classified as CWE-248 (CWE-248). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-vxx9-2994-q338 published, and has it been updated?

GHSA-vxx9-2994-q338 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

GHSA-vxx9-2994-q338 — yamux

GHSA-vxx9-2994-q338 is a CWE-248 vulnerability in yamux. A fix is available for yamux — see the affected versions and patch details below.

Yamux vulnerable to remote Panic via malformed Data frame with SYN set and len = 262145

Also known asCVE-2026-32314

Published

Mar 13, 2026

Updated

Mar 16, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 24, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
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-vxx9-2994-q338.

EPSS Exploitation Probability

via FIRST.org ↗

0.6%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs45th percentile — riskier than 45% of all scored CVEsHighest risk

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.

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

Summary

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. kind of vulnerability is it? Who is

Attack Scenario

An attacker that can establish a Yamux session with a target node can crash the target by sending a single validly encoded Yamux Data|SYN frame with an oversized body:

Establish a standard authenticated transport session that negotiates Yamux.
Send one Yamux frame with:
- Tag = Data
- Flags = SYN
- StreamId = 1 (or any new inbound stream id)
- Length = DEFAULT_CREDIT + 1 (e.g. 262145)
- Body of matching size This can trigger a panic (stream not found) and terminate the process, depending on host application panic policy.

Patches

Users should upgrade to yamux v0.13.10

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`	all versions	0.13.10`cargo update -p yamux --precise 0.13.10`

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 0.13.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-vxx9-2994-q338 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-vxx9-2994-q338 can be triaged on real exposure rather than presence alone.

Tailored to GHSA-vxx9-2994-q338. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary 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. kind of vulnerability

O3 Security · Impact-Aware SCA

Is GHSA-vxx9-2994-q338 in your dependencies?

O3 Security finds GHSA-vxx9-2994-q338 across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works