# From Exploit Code to Production Detection: Building a CVE-2026-31431 (Copy Fail) detection with Agents

DevFeed: [From Exploit Code to Production Detection: Building a CVE-2026-31431 (Copy Fail) detection with Agents](<https://devfeed.tech/articles/from-exploit-code-to-production-detection-building-a-cve-2026-31431-copy-fail-detection-with-agents-8284.md>)

Original publisher: [Read original article](<https://securitylabs.datadoghq.com/articles/cve-2026-31431-copy-fail-exploit-detection-with-agents/>)

Author: Ryan Simon

Published: 2026-05-28T00:00:00Z

Content type: article

Language: en

Sources: [Datadog Security Labs](<https://devfeed.tech/sources/datadog-security-labs.md>)

Topics: [Vulnerabilities](<https://devfeed.tech/topics/vulnerabilities.md>), [Linux](<https://devfeed.tech/topics/linux.md>), [Detection engineering](<https://devfeed.tech/topics/detection-engineering.md>), [kernels](<https://devfeed.tech/topics/kernels.md>), [Security](<https://devfeed.tech/topics/security.md>), [AI-assisted coding](<https://devfeed.tech/topics/ai-assisted-coding.md>), [Cryptography](<https://devfeed.tech/topics/cryptography.md>)

Tags: [agents](<https://devfeed.tech/tags/agents.md>), [analysis](<https://devfeed.tech/tags/analysis.md>), [audit-trail](<https://devfeed.tech/tags/audit-trail.md>), [code](<https://devfeed.tech/tags/code.md>), [coding](<https://devfeed.tech/tags/coding.md>), [engineering](<https://devfeed.tech/tags/engineering.md>), [kernel](<https://devfeed.tech/tags/kernel.md>), [kernels](<https://devfeed.tech/tags/kernels.md>), [linux](<https://devfeed.tech/tags/linux.md>), [operations](<https://devfeed.tech/tags/operations.md>), [security](<https://devfeed.tech/tags/security.md>), [vulnerabilities](<https://devfeed.tech/tags/vulnerabilities.md>), [vulnerability](<https://devfeed.tech/tags/vulnerability.md>)

## AI overview

CVE-2026-31431, known as Copy Fail, allows an unprivileged local user to corrupt Linux page caches through AF_ALG sockets and escalate privileges to execute code as root. The article explains the exploit's kernel mechanisms and describes how Datadog Security Research used coding agents to develop and ship a detection in a single session.

## Source excerpt

CVE-2026-31431 (Copy Fail) lets any unprivileged user corrupt the Linux page cache via AF_ALG sockets to escalate privileges. This post covers the exploit mechanics and how Datadog Security Research used coding agents to ship a detection content pack in a single session.