---
id: CVE-2026-39829
title: >-
  The RSA and DSA public key parsers did not enforce size limits on key
  parameters
summary: >-
  The RSA and DSA public key parsers did not enforce size limits on key
  parameters. A crafted public key with an excessively large modulus or DSA
  parameter could cause several minutes of CPU consumption during signature
  verification. This …
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-347
  - CWE-1284
  - CWE-1176
vendor: golang
product: crypto
affected:
  - crypto < 0.52.0
patched:
  - crypto 0.52.0
published: '2026-05-22'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T13:17:52.280'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-39829'
references:
  - url: 'https://go.dev/cl/781641'
    label: security@golang.org
  - url: 'https://go.dev/cl/781661'
    label: security@golang.org
  - url: 'https://go.dev/issue/79565'
    label: security@golang.org
  - url: 'https://groups.google.com/g/golang-announce/c/a082jnz-LvI'
    label: security@golang.org
  - url: 'https://pkg.go.dev/vuln/GO-2026-5018'
    label: security@golang.org
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  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-39829'
  - url: 'https://github.com/advisories/GHSA-w879-237q-wc7r'
tags:
  - nvd
  - cve.org
  - ghsa
  - go
  - osv
epss: 0.00623
epssPercentile: 0.47563
ecosystem: go
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-05-22T18:52:38.155082Z'
ingestedAt: '2026-06-26T16:43:14.195Z'
aliases:
  - GO-2026-5018
  - GHSA-w879-237q-wc7r
---

## Overview

The RSA and DSA public key parsers did not enforce size limits on key parameters. A crafted public key with an excessively large modulus or DSA parameter could cause several minutes of CPU consumption during signature verification. This could be triggered by unauthenticated clients during public key authentication. RSA moduli are now limited to 8192 bits, and DSA parameters are validated per FIPS 186-2.

## Affected

- `crypto < 0.52.0`

## Remediation

Upgrade past the affected range:

- `crypto 0.52.0`

## Package advisory (CVE-2026-39829)

Affected packages:

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

Patched in:

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

Source: https://github.com/advisories/GHSA-w879-237q-wc7r