Cyber Resilience

CVE-2026-39828

Crypto Weakness in Golang Crypto ≤ 0.52.0

Crypto Weakness
Published
22 May 2026
Modified
13 August 2026
Patch / advisory
View advisory
CVSS Score v3.1 6.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
EPSS Score 0.0037 30th percentile
Risk Priority 48 floored blend · peak EPSS

Summary

CVE-2026-39828 is a medium-severity Improper Certificate Validation (CWE-295) vulnerability in Golang Crypto. Its CVSS base score is 6.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Adversary-in-the-Middle (T1557); ranked at the 30th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-16 (Security and Privacy Attributes) and SC-17 (Public Key Infrastructure Certificates) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A01:2025 Broken Access ControlA07:2025 Authentication Failures

EU & UK References

Vulnerability Data

When an SSH server authentication callback returned PartialSuccessError with non-nil Permissions, those permissions were silently discarded, potentially dropping certificate restrictions such as force-command after a second factor succeeded. Returning non-nil Permissions with PartialSuccessError now results in a connection error.

CWE(s)
CWE-295CWE-281

Related Threats

MITRE ATT&CK Enterprise Techniques

T1557 Adversary-in-the-Middle Credential Access
Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as [Network Sniffing](https://attack.
attack.mitre.org →
T1557.002 ARP Cache Poisoning Credential Access
Adversaries may poison Address Resolution Protocol (ARP) caches to position themselves between the communication of two or more networked devices.
attack.mitre.org →
T1557.003 DHCP Spoofing Credential Access
Adversaries may redirect network traffic to adversary-owned systems by spoofing Dynamic Host Configuration Protocol (DHCP) traffic and acting as a malicious DHCP server on the victim network.
attack.mitre.org →
T1557.004 Evil Twin Credential Access
Adversaries may host seemingly genuine Wi-Fi access points to deceive users into connecting to malicious networks as a way of supporting follow-on behaviors such as [Network Sniffing](https://attack.
attack.mitre.org →
T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
attack.mitre.org →
T1039 Data from Network Shared Drive Collection
Adversaries may search network shares on computers they have compromised to find files of interest.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-42508Same product: Golang Crypto
CVE-2026-39832Same product: Golang Crypto
CVE-2026-39835Same product: Golang Crypto
CVE-2026-39827Same product: Golang Crypto
CVE-2026-46597Same product: Golang Crypto
CVE-2025-58181Same product: Golang Crypto
CVE-2026-39829Same product: Golang Crypto
CVE-2026-39834Same product: Golang Crypto
CVE-2026-39831Same product: Golang Crypto
CVE-2026-39833Same product: Golang Crypto

Affected Assets

golang
crypto
≤ 0.52.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 20 hardening rules · 6 OS baselines
Validate
Prove the fix (OWASP ASVS)

—

Mitigating Controls (NIST 800-53 r5) AI

AC-16 Security and Privacy Attributes good match

Associating and preserving security attributes (including permissions) with objects reduces the chance they are lost or weakened on copy/restore/share.

SC-17 Public Key Infrastructure Certificates good match

PKI certificate issuance and acquisition under an approved policy establishes the trusted roots and processes needed for correct validation.

AC-3 Access Enforcement partial match

Enforcing approved authorizations for access directly stops objects from receiving or retaining less-restrictive permissions than intended.

AC-6 Least Privilege partial match

Least-privilege assignments limit the blast radius when permissions are incorrectly relaxed during copy/restore/share operations.

SC-23 Session Authenticity partial match

Protecting session authenticity depends on cryptographic mechanisms whose trust depends on correct certificate validation.

SC-8 Transmission Confidentiality and Integrity partial match

Requiring confidentiality and integrity protection of transmitted data drives use of properly validated certificates in protocols such as TLS.

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.AA-03 mostly match
prevents

Certificate-based authentication of users/services/hardware directly depends on correct validation.

PR.AA-05 mostly match
prevents

Enforcing least-privilege permission policies and reviews directly prevents incorrect permission propagation on copy/restore/share operations.

PR.DS-02 mostly match
prevents

Proper certificate validation is a core mechanism for protecting data-in-transit confidentiality and integrity.

PR.PS-06 mostly match
prevents

Secure development practices explicitly include implementing correct certificate validation logic.

ID.RA-09 partial match
prevents

Assessing authenticity/integrity of acquired software often relies on code-signing certificate validation.

PR.AA-04 partial match
prevents

Identity assertions conveyed via certificates require validation to be verified.

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.5.15 Access control partial match
degrades

Access-control policy defines how permissions must be preserved when objects are copied or shared.

A.5.18 Access rights partial match
degrades

Access-rights provisioning and review processes directly address the risk of overly permissive copied objects.

A.8.2 Privileged access rights partial match
degrades

Privileged-access management includes rules for maintaining correct permissions on copied or restored data.

A.8.24 Use of cryptography partial match
prevents

Requiring issuance and validation of public-key certificates under an approved policy reduces the chance that certificates with improper validation will be trusted.

A.8.3 Information access restriction partial match
degrades

Information-access-restriction controls enforce least-privilege permissions that must be preserved during copy/restore operations.

A.8.32 Change management none match
none

Change-management procedures can require verification that permissions remain intact after modifications or restores.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (3 rules)
  • V-248574 YUM must be configured to prevent the installation of patches, service packs, device drivers, or OL 8 system components that have not been digitally signed using a certificate that is recognized and approved by the organization. prevents CWE-295
  • V-248531 OL 8, for PKI-based authentication, must validate certificates by constructing a certification path (which includes status information) to an accepted trust anchor. prevents CWE-295
  • V-248575 OL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-295
RHEL 7 (2 rules)
  • V-204447 The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-295
  • V-204448 The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-295
RHEL 8 (2 rules)
  • V-230264 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-295
  • V-230265 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-295
Windows Server 2019 (1 rule)
  • V-205743 Windows Server 2019 organization created Active Directory Organizational Unit (OU) objects must have proper access control permissions. prevents CWE-281
Windows Server 2022 (2 rules)
  • V-254393 Windows Server 2022 Active Directory Group Policy objects must have proper access control permissions. prevents CWE-281
  • V-254395 Windows Server 2022 organization created Active Directory Organizational Unit (OU) objects must have proper access control permissions. prevents CWE-281

References