CVE-2026-31814: Yamux Yamux Vulnerable To Remote Panic Vulnerability

HIGH
Advisory Identifier: GHSA-4w32-2493-32g7
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CWE-190
Published
Advisory Summary

CVE-2026-31814 is a HIGH yamux vulnerable to remote panic vulnerability (CWE-190: Integer Overflow or Wraparound) affecting Yamux libraries in the crates.io ecosystem. The issue involves yamux vulnerable to remote panic via malformed windowupdate credit. Remediation is available by upgrading affected packages to version 0.13.9.

CVE-2026-31814 at a Glance

CVE Identifier CVE-2026-31814
GHSA Identifier GHSA-4w32-2493-32g7
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-190: Integer Overflow or Wraparound
Affected Product Yamux
Package Ecosystem crates.io
Published Date
Last Updated

How to Fix CVE-2026-31814

To remediate this vulnerability, upgrade all affected Yamux dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

yamux fixed: 0.13.9 
Upgrade yamux to 0.13.9
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for yamux

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-31814, inspect your project dependencies for Yamux:

inspect dependencies for yamux

Analyze the terminal output to locate any version of Yamux in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.13.9), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-190: Integer Overflow or Wraparound, where the product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. this occurs when an integer value is incremented to a value that is too large to store in the associated representation. when this occurs, the value may become a very small or negative number. In Yamux, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### 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 stream exists with initial send-window state (`DEFAULT_CREDIT`). 2. 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

CVE-2026-31814 Affected Yamux Versions

1 component(s)
Fixed Versions:
0.13.9
Product / Package Ecosystem Affected Versions Fixed Version
yamux
 crates.io
≥ 0.13.0
< 0.13.9
0.13.9

References

GitHub Advisory / Wiki ADVISORY
https://github.com/libp2p/rust-yamux/security/advisories/GHSA-4w32-2493-32g7
NVD — CVE-2026-31814 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-31814
Yamux Source Repository REPOSITORY
https://github.com/libp2p/rust-yamux/pull/221
Security Fix Commit FIX COMMIT
https://github.com/libp2p/rust-yamux/commit/b1aae09d60c0bd6a5915a5448f4e8cbc5174db53
Yamux Source Repository REPOSITORY
https://github.com/libp2p/rust-yamux
Yamux Release RELEASE
https://github.com/libp2p/rust-yamux/releases/tag/yamux-v0.13.9

Frequently Asked Questions

What is CVE-2026-31814?
CVE-2026-31814 is a security vulnerability in Yamux involving Yamux vulnerable to remote Panic via malformed WindowUpdate credit under CWE-190: Integer Overflow or Wraparound.
Which Yamux versions are affected?
Affected versions include releases prior to 0.13.9 across affected packages: yamux.
What version fixes CVE-2026-31814?
Upgrading to 0.13.9 (or the latest patched release for your respective branch) resolves the vulnerability.
Is yamux affected?
Yes, yamux is affected in releases prior to 0.13.9. Upgrade your dependency to 0.13.9 or later.
What CWE is associated with CVE-2026-31814?
CVE-2026-31814 is classified under CWE-190: Integer Overflow or Wraparound (The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.).
How can I check crates.io dependencies for CVE-2026-31814?
Run the dependency tree command: 'inspect dependencies for yamux'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-4w32-2493-32g7",
  "modified" : "2026-03-16T17:06:20Z",
  "published" : "2026-03-13T18:57:19Z",
  "aliases" : [ "CVE-2026-31814" ],
  "summary" : "Yamux vulnerable to remote Panic via malformed WindowUpdate credit",
  "details" : "### Sumary\nThe Rust implementation of Yamux accepts `WindowUpdate` credit values from the remote peer and applies them to per-stream send-window state.  \nA 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.\n#### Attack Scenario  \nAn attacker that can establish a Yamux session with a target node can crash the target by sending two validly encoded Yamux frames:\n1. Open a stream (e.g. DATA + SYN) so the stream exists with initial send-window state (`DEFAULT_CREDIT`).\n2. 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.\n### Impact\nRemote unauthenticated denial of service.  \nAn attacker can repeatedly trigger panics by reconnecting and replaying the crafted frame sequence.\n### Patches\nUsers should upgrade to `yamux` `v0.13.9`\n\nThis vulnerability was originally submitted by @revofusion to the Ethereum Foundation bug bounty program",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "yamux"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.13.0"
      }, {
        "fixed" : "0.13.9"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/libp2p/rust-yamux/security/advisories/GHSA-4w32-2493-32g7"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-31814"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/libp2p/rust-yamux/pull/221"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/libp2p/rust-yamux/commit/b1aae09d60c0bd6a5915a5448f4e8cbc5174db53"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/libp2p/rust-yamux"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/libp2p/rust-yamux/releases/tag/yamux-v0.13.9"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-190" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-13T18:57:19Z",
    "nvd_published_at" : "2026-03-13T19:54:36Z"
  }
}