---
id: CVE-2026-39834
aliases:
  - GO-2026-5020
  - GHSA-rm3j-f69w-wqmq
title: Invoking infinite loop on large channel writes in golang.org/x/crypto/ssh
summary: Invoking infinite loop on large channel writes in golang.org/x/crypto/ssh
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
vendor: x
product: golang.org/x/crypto
ecosystem: go
affected:
  - golang.org/x/crypto < 0.52.0
patched:
  - golang.org/x/crypto 0.52.0
published: '2026-05-22'
updated: '2026-09-22'
sourceUpdated: '2026-09-22T10:41:48.726876657Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GO-2026-5020'
references:
  - url: 'https://go.dev/issue/79567'
  - url: 'https://groups.google.com/g/golang-announce/c/a082jnz-LvI'
  - url: 'https://go.dev/cl/781663'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39834.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-39834'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2480676'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-39834'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-39834'
  - url: 'https://pkg.go.dev/vuln/GO-2026-5020'
  - url: 'https://access.redhat.com/errata/RHSA-2026:43692'
  - url: 'https://access.redhat.com/errata/RHSA-2026:62391'
  - url: 'https://access.redhat.com/errata/RHSA-2026:66561'
  - url: 'https://access.redhat.com/errata/RHSA-2026:37387'
  - url: 'https://access.redhat.com/errata/RHSA-2026:57194'
  - url: 'https://github.com/advisories/GHSA-rm3j-f69w-wqmq'
tags:
  - osv
  - go
  - csaf
  - vex
  - red-hat
  - ghsa
  - score-dispute
epss: 0.00637
epssPercentile: 0.48247
cvssSource: vendor
cwe:
  - CWE-190
scores:
  vendor: 6.5
  ghsa: 9.1
ingestedAt: '2026-06-26T16:43:14.192Z'
---

## Overview

When writing data larger than 4GB in a single Write call on an SSH channel, an integer overflow in the internal payload size calculation caused the write loop to spin indefinitely, sending empty packets without making progress. The size comparison now uses int64 to prevent truncation.

## Affected packages

- `golang.org/x/crypto < 0.52.0`

## Remediation

Upgrade to a patched release:

- `golang.org/x/crypto 0.52.0`

## Vendor advisories

- **RHSA-2026:43692** · Red Hat · fixed in: OpenShift API for Data Protection 1.6 · released 2026-07-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:43692)
- **RHSA-2026:62391** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-02 · [advisory](https://access.redhat.com/errata/RHSA-2026:62391)
- **RHSA-2026:66561** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-11 · [advisory](https://access.redhat.com/errata/RHSA-2026:66561)
- **RHSA-2026:37387** · Red Hat · fixed in: Red Hat Openshift Data Foundation 4.22 · released 2026-07-09 · [advisory](https://access.redhat.com/errata/RHSA-2026:37387)
- **RHSA-2026:57194** · Red Hat · fixed in: multicluster engine for Kubernetes 2.11 · released 2026-08-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:57194)
- **Red Hat VEX** · Moderate · affected: Builds for Red Hat OpenShift, Cryostat 4, OpenShift Pipelines, OpenShift Serverless, Red Hat Ceph Storage 5, Red Hat Ceph Storage 6, … · no fix planned: Red Hat Hardened Images, Builds for Red Hat OpenShift, Cryostat 4, OpenShift Pipelines, … · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39834.json)