Cyber Resilience

CVE-2026-31814

Memory Safety in Protocol Yamux 0.13.0 – 0.13.9

Public PoCMemory Safety
Published
13 March 2026
Modified
19 March 2026
Patch / advisory
View advisory
CVSS Score v4 8.7
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0046 38th percentile
Risk Priority 44 floored blend · peak EPSS

Summary

CVE-2026-31814 is a high-severity Integer Overflow or Wraparound (CWE-190) vulnerability in Protocol Yamux. Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 38th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-31814 affects Yamux, a stream multiplexer over reliable, ordered connections such as TCP/IP, specifically in the rust-yamux implementation from versions 0.13.0 up to but not including 0.13.9. The vulnerability stems from an arithmetic overflow (CWE-190) in send-window accounting, triggered by a specially crafted WindowUpdate frame. This causes a panic in the connection state machine, rated at CVSS 3.1 score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Any remote attacker can exploit this over a normal network connection without authentication by sending the crafted WindowUpdate frame. Successful exploitation results in a denial-of-service condition, crashing the affected Yamux connection and potentially disrupting services relying on it for stream multiplexing.

The vulnerability is fixed in Yamux version 0.13.9. Security practitioners should upgrade to this version or later. Additional details are available in the GitHub Security Advisory at https://github.com/libp2p/rust-yamux/security/advisories/GHSA-4w32-2493-32g7.

EU & UK References

Vulnerability Data

Yamux is a stream multiplexer over reliable, ordered connections such as TCP/IP. From 0.13.0 to before 0.13.9, a specially crafted WindowUpdate can cause arithmetic overflow in send-window accounting, which triggers a panic in the connection state machine. This is remotely…

more

reachable over a normal network connection and does not require authentication. This vulnerability is fixed in 0.13.9.

CWE(s)
CWE-190

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-32314Same product: Protocol Yamux
CVE-2026-33040Same vendor: Protocol
CVE-2026-34219Same vendor: Protocol
CVE-2023-22460Same vendor: Protocol
CVE-2024-49994Shared CWE-190
CVE-2026-37540Shared CWE-190
CVE-2026-24210Shared CWE-190
CVE-2026-53482Shared CWE-190
CVE-2024-26817Shared CWE-190
CVE-2025-22081Shared CWE-190

Affected Assets

protocol
yamux
0.13.0 — 0.13.9

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V5.2.6

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation (static analysis, fuzzing, unit tests) directly finds integer overflow defects before deployment.

SA-8 Security and Privacy Engineering Principles partial match

Secure engineering principles require use of safe arithmetic constructs or language features that structurally eliminate integer overflow during calculation.

SI-10 Information Input Validation partial match

Input validation enforces bounds on values before arithmetic, stopping the conditions that trigger overflow or wraparound.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require use of safe arithmetic, bounds checks, and testing that prevent integer overflows.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development can detect integer overflows before release.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC mandates input validation and arithmetic checks that prevent integer overflows.

A.8.26 Application security requirements partial match
degrades

Application security requirements include bounds checking and safe arithmetic to avoid overflow conditions.

A.8.27 Secure system architecture and engineering principles partial match
degrades

Secure architecture principles require defensive coding patterns that mitigate integer wraparound risks.

A.8.28 Secure coding partial match
prevents

Secure coding standards explicitly forbid unsafe integer operations and mandate overflow-safe constructs.

References