CVE-2026-39833

Invoking key constraints not enforced in golang.org/x/crypto/ssh/agent

Published: May 22, 2026Updated: Aug 11, 2026 Sources: CVE List NVDCWE-862

9.1CRITICAL

Description

The in-memory keyring returned by NewKeyring() silently accepted keys with the ConfirmBeforeUse constraint but never enforced it. The key would sign without any confirmation prompt, with no indication to the caller that the constraint was not in effect. NewKeyring() now returns an error when unsupported constraints are requested.

No summary for this CVE yet.

CVSS Vector Breakdown

Exploitability

AV:NAttack Vector

Network

AC:LAttack Complexity

Low

PR:NPrivileges Required

None

UI:NUser Interaction

None

Scope

S:UScope

Unchanged

Impact

C:HConfidentiality

High

I:HIntegrity

High

A:NAvailability

None

Open in CVSS calculator →

Weaknesses

CWE-862

Affected Products

golang.org/x/crypto

oss-projectaka golang x crypto, x/crypto

golang.org/x/crypto/ssh/agentLibrary

oss-project·US

Exploitability

Official Patch Available

Is your org exposed to CVE-2026-39833?Request an assessment to establish which checks are appropriate for your systems. Check my exposure

Attack Graph

Products CVE Techniques Tactics

Click technique nodes for MITRE ATT&CK details · drag to pan · Ctrl/⌘ + scroll to zoom, or go fullscreen.

MITRE ATT&CK

2 techniques

Initial Access

View detailed technique mapping

References

https://go.dev/issue/79436

go.dev

https://go.dev/cl/778642

go.dev

https://groups.google.com/g/golang-announce/c/a082jnz-LvI

groups.google.com

and 1 more references View all →

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2026-39833 and every CVE in our database. Create a free account — no credit card required.

Create Free Account

Plain-language analysis

Impact assessment and exploitation scenario in plain English

Attack graph visualization

Interactive attack path and kill chain mapping

Exploit details & PoC links

ExploitDB, Metasploit, GitHub PoCs with direct links

Nuclei scanner templates

Ready-to-use vulnerability scanner templates

Full remediation guide

Patch instructions, workarounds, and compliance impact

Interactive AI chat

Ask questions about this vulnerability in natural language

Related vulnerabilities

Semantically similar CVEs and attack patterns

REST API & MCP access

Integrate vulnerability data into your workflows