Linux Kernel Flaw "Copy Fail" PoC Public
A local privilege-escalation vulnerability in the Linux kernel, dubbed Copy Fail (CVE-2026-31431), has public exploit code available, IPA warns.
Sourceipa.go.jp — open the original
What to check
- Applies to
- The 1 CVE named below. Whether you run an affected version is not assessed: check the versions the source lists.
- Exploitation
- CISA lists CVE-2026-31431 as exploited in the wild.
Japan's IPA has issued an alert on CVE-2026-31431, nicknamed "Copy Fail," a privilege-escalation vulnerability affecting the Linux kernel from version 4.14 onward. The flaw requires local, low-privileged access (CVSS vector AV:L, PR:L) and is not remotely exploitable, but a successful exploit allows an already-authenticated local user to escalate to administrator/root privileges.
IPA notes that proof-of-concept exploit code for the vulnerability is already publicly available, raising the risk of exploitation, particularly when chained with other vulnerabilities or in multi-tenant environments such as shared containerized systems where multiple users share a kernel. The advisory does not indicate evidence of active in-the-wild exploitation but flags the public PoC as a significant risk factor.
IPA advises organizations to monitor distribution-specific advisories for patch availability and apply updates promptly. Where patches are not yet available, vendors may offer workarounds, though IPA cautions that these should be thoroughly tested before deployment due to potential operational impact.
Mentioned in this report
Source reporting: https://www.ipa.go.jp/security/security-alert/2026/alert20260501.html
Free public brief. Slack alerts on the vendors you run come with the paid plans, and a new account gets three days of them, no card.
What this brief leaves out
This page is the free tier: the write-up, the severity, the names. In the app the same report carries live profiles of the CVEs it names. The paid plans add the security research and news reporting the free tier leaves out.
It sits in a corpus of 16,433 reports from 149 sources, 661 of them written in the last seven days, and it grows through the day.
A new account starts with three days of all of it, no card, then keeps the government and CERT reporting free. Slack alerts are a paid-plan feature: name the vendors you run and Slack hears about the reports that touch them, not the rest of the week's. Nothing is charged unless you subscribe.
Create a free account What it costs