x-crypto up to 0.51.x Key Call null pointer dereference

Summaryinfo

A vulnerability identified as problematic has been detected in x-crypto up to 0.51.x. The affected element is an unknown function of the component Key Call Handler. The manipulation leads to null pointer dereference. This vulnerability is traded as CVE-2026-39835. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in x-crypto up to 0.51.x. It has been rated as problematic. This issue affects some unknown functionality of the component Key Call Handler. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is availability. The summary by CVE is:

SSH servers which use CertChecker as a public key callback without setting IsUserAuthority or IsHostAuthority could be caused to panic by a client presenting a certificate. CertChecker now returns an error instead of panicking when these callbacks are nil.

The advisory is shared at go.dev. The identification of this vulnerability is CVE-2026-39835 since 04/07/2026. Neither technical details nor an exploit are publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 316604 (Linux Distros Unpatched Vulnerability : CVE-2026-39835), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 0.52.0 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (316604), EUVD (EUVD-2026-31393) and CERT Bund (WID-SEC-2026-1653). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• Amazon Linux 2
• Red Hat Enterprise Linux
• Fedora Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• RESF Rocky Linux
• IBM MQ
• Golang Go
• SUSE openSUSE
• Red Hat OpenShift

Productinfo

Name

• x-crypto

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10
• 0.11
• 0.12
• 0.13
• 0.14
• 0.15
• 0.16
• 0.17
• 0.18
• 0.19
• 0.20
• 0.21
• 0.22
• 0.23
• 0.24
• 0.25
• 0.26
• 0.27
• 0.28
• 0.29
• 0.30
• 0.31
• 0.32
• 0.33
• 0.34
• 0.35
• 0.36
• 0.37
• 0.38
• 0.39
• 0.40
• 0.41
• 0.42
• 0.43
• 0.44
• 0.45
• 0.46
• 0.47
• 0.48
• 0.49
• 0.50
• 0.51

CPE 2.3info

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CPE 2.2info

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CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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