CVE-2026-39829: Golang.org/x/crypto Denial of Service Vulnerability

HIGH
Advisory Identifier: GHSA-w879-237q-wc7r
CVSS 7.5
CWE-1284 CWE-347
Published
Advisory Summary

CVE-2026-39829 is a HIGH (CVSS 7.5) denial of service vulnerability (CWE-1284: Improper Validation of Specified Quantity in Input) affecting Golang.org/x/crypto libraries in the Go ecosystem. The issue involves invoking pathological rsa/dsa parameters may cause dos. Remediation is available by upgrading affected packages to version 0.52.0.

CVE-2026-39829 at a Glance

CVE Identifier CVE-2026-39829
GHSA Identifier GHSA-w879-237q-wc7r
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-1284: Improper Validation of Specified Quantity in Input
Affected Product Golang.org/x/crypto
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-39829

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

golang.org/x/crypto fixed: 0.52.0
Upgrade golang.org/x/crypto to 0.52.0
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 golang.org/x/crypto

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-39829, inspect your project dependencies for Golang.org/x/crypto:

inspect dependencies for golang.org/x/crypto

Analyze the terminal output to locate any version of Golang.org/x/crypto in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.52.0), 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-1284: Improper Validation of Specified Quantity in Input, where the product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties. In Golang.org/x/crypto, 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

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.

CVE-2026-39829 Affected Golang.org/x/crypto Versions

1 component(s)
Fixed Versions:
0.52.0
Product / Package Ecosystem Affected Versions Fixed Version
golang.org/x/crypto
Go
< 0.52.0
0.52.0

References

NVD — CVE-2026-39829 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-39829
access.redhat.com/errata/rhsa-2026:37... WEB
https://access.redhat.com/errata/RHSA-2026:37387
access.redhat.com/errata/rhsa-2026:40... WEB
https://access.redhat.com/errata/RHSA-2026:40118
access.redhat.com/errata/rhsa-2026:40... WEB
https://access.redhat.com/errata/RHSA-2026:40119
access.redhat.com/errata/rhsa-2026:40... WEB
https://access.redhat.com/errata/RHSA-2026:40262
access.redhat.com/errata/rhsa-2026:40... WEB
https://access.redhat.com/errata/RHSA-2026:40945
access.redhat.com/errata/rhsa-2026:40... WEB
https://access.redhat.com/errata/RHSA-2026:40969
access.redhat.com/errata/rhsa-2026:40... WEB
https://access.redhat.com/errata/RHSA-2026:40972
access.redhat.com/errata/rhsa-2026:40... WEB
https://access.redhat.com/errata/RHSA-2026:40974
access.redhat.com/errata/rhsa-2026:41... WEB
https://access.redhat.com/errata/RHSA-2026:41019
access.redhat.com/errata/rhsa-2026:41... WEB
https://access.redhat.com/errata/RHSA-2026:41031
access.redhat.com/errata/rhsa-2026:41... WEB
https://access.redhat.com/errata/RHSA-2026:41036
go.dev/cl/781641 WEB
https://go.dev/cl/781641
access.redhat.com/errata/rhsa-2026:41... WEB
https://access.redhat.com/errata/RHSA-2026:41055
access.redhat.com/errata/rhsa-2026:41... WEB
https://access.redhat.com/errata/RHSA-2026:41066
Golang.org/x/crypto Security Information SECURITY
https://access.redhat.com/security/cve/CVE-2026-39829
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=2480681
cs.opensource.google/go/x/crypto PACKAGE
https://cs.opensource.google/go/x/crypto
go.dev/cl/781661 WEB
https://go.dev/cl/781661
go.dev/issue/79565 WEB
https://go.dev/issue/79565
groups.google.com/g/golang-announce/c... WEB
https://groups.google.com/g/golang-announce/c/a082jnz-LvI
pkg.go.dev/vuln/go-2026-5018 WEB
https://pkg.go.dev/vuln/GO-2026-5018
Golang.org/x/crypto Security Information SECURITY
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39829.json
access.redhat.com/errata/rhsa-2026:26... WEB
https://access.redhat.com/errata/RHSA-2026:26546
access.redhat.com/errata/rhsa-2026:26... WEB
https://access.redhat.com/errata/RHSA-2026:26547
access.redhat.com/errata/rhsa-2026:29... WEB
https://access.redhat.com/errata/RHSA-2026:29455
access.redhat.com/errata/rhsa-2026:35... WEB
https://access.redhat.com/errata/RHSA-2026:35833
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36199
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36207
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36319
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36625
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36648
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36651
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36796
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36797
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36808
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36820
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36883
access.redhat.com/errata/rhsa-2026:37... WEB
https://access.redhat.com/errata/RHSA-2026:37072
access.redhat.com/errata/rhsa-2026:37... WEB
https://access.redhat.com/errata/RHSA-2026:37123
access.redhat.com/errata/rhsa-2026:37... WEB
https://access.redhat.com/errata/RHSA-2026:37268
access.redhat.com/errata/rhsa-2026:37... WEB
https://access.redhat.com/errata/RHSA-2026:37271
access.redhat.com/errata/rhsa-2026:37... WEB
https://access.redhat.com/errata/RHSA-2026:37272
access.redhat.com/errata/rhsa-2026:37... WEB
https://access.redhat.com/errata/RHSA-2026:37278
access.redhat.com/errata/rhsa-2026:37... WEB
https://access.redhat.com/errata/RHSA-2026:37286
access.redhat.com/errata/rhsa-2026:37... WEB
https://access.redhat.com/errata/RHSA-2026:37296

Frequently Asked Questions

What is CVE-2026-39829?
CVE-2026-39829 is a security vulnerability in Golang.org/x/crypto involving Invoking pathological RSA/DSA parameters may cause DoS under CWE-1284: Improper Validation of Specified Quantity in Input.
Which Golang.org/x/crypto versions are affected?
Affected versions include releases prior to 0.52.0 across affected packages: golang.org/x/crypto.
What version fixes CVE-2026-39829?
Upgrading to 0.52.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is golang.org/x/crypto affected?
Yes, golang.org/x/crypto is affected in releases prior to 0.52.0. Upgrade your dependency to 0.52.0 or later.
What is the CVSS score of CVE-2026-39829?
CVE-2026-39829 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-39829?
CVE-2026-39829 is classified under CWE-1284: Improper Validation of Specified Quantity in Input (The product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties.).
How can I check Go dependencies for CVE-2026-39829?
Run the dependency tree command: 'inspect dependencies for golang.org/x/crypto'. 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
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-w879-237q-wc7r",
  "modified" : "2026-07-20T12:32:55Z",
  "published" : "2026-06-25T22:18:43Z",
  "aliases" : [ "CVE-2026-39829" ],
  "summary" : "golang.org/x/crypto: Invoking pathological RSA/DSA parameters may cause DoS",
  "details" : "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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "golang.org/x/crypto"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.52.0"
      } ]
    } ]
  } ],
  "references" : [ {
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  }, {
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  "database_specific" : {
    "cwe_ids" : [ "CWE-1284", "CWE-347" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-25T22:18:43Z",
    "nvd_published_at" : "2026-05-22T04:16:22Z"
  }
}