Linux Kernel Elevation of Privilege Vulnerability
RISK: Medium Risk
TYPE: Operating Systems - Linux

A vulnerability was identified in Linux Kernel. A local attacker can exploit this vulnerability to trigger elevation of privilege on the targeted system.
Note:
CVE-2026-31431 is being exploited in the wild. Copy Fail (CVE-2026-31431) is a logic bug in the Linux kernel's authencesn cryptographic template. It lets an unprivileged local user trigger a deterministic, controlled 4-byte write into the page cache of any readable file on the system. A single 732-byte Python script can edit a setuid binary and obtain root on essentially all Linux distributions shipped since 2017.
[Updated on 2026-05-11]
Updated System / Technologies affected, Solutions, Source and Related Links.
[Updated on 2026-05-14]
Updated System / Technologies affected, Solutions, Source and Related Links.
Impact
- Elevation of Privilege
System / Technologies affected
- Ubuntu: https://ubuntu.com/security/CVE-2026-31431
- Debian: https://security-tracker.debian.org/tracker/CVE-2026-31431
- Red Hat: https://access.redhat.com/security/cve/cve-2026-31431
- SUSE: https://www.suse.com/security/cve/CVE-2026-31431.html
- Amazon: https://explore.alas.aws.amazon.com/CVE-2026-31431.html
- Arch: https://security.archlinux.org/CVE-2026-31431
- AlmaLinux: https://almalinux.org/blog/2026-05-01-cve-2026-31431-copy-fail/
- Cloudlinux: https://blog.cloudlinux.com/cve-2026-31431-copy-fail-mitigation-and-patches
- Fortinet: https://fortiguard.fortinet.com/psirt/FG-IR-26-139
- Gentoo: https://bugs.gentoo.org/show_bug.cgi?id=CVE-2026-31431
- Juniper: https://supportportal.juniper.net/s/article/2026-05-Reference-Advisory-Status-of-Copy-Fail-vulnerability-on-Juniper-Products-CVE-2026-31431
- QNAP: https://www.qnap.com/zh-hk/security-advisory/qsa-26-16
Solutions
Before installation of the software, please visit the software vendor web-site for more details.
Apply fixes issued by the vendor:
- Ubuntu: https://ubuntu.com/security/CVE-2026-31431
- Debian: https://security-tracker.debian.org/tracker/CVE-2026-31431
- Red Hat: https://access.redhat.com/security/cve/cve-2026-31431
- SUSE: https://www.suse.com/security/cve/CVE-2026-31431.html
- Amazon: https://explore.alas.aws.amazon.com/CVE-2026-31431.html
- Arch: https://security.archlinux.org/CVE-2026-31431
- AlmaLinux: https://almalinux.org/blog/2026-05-01-cve-2026-31431-copy-fail/
- Cloudlinux: https://blog.cloudlinux.com/cve-2026-31431-copy-fail-mitigation-and-patches
- Fortinet: https://fortiguard.fortinet.com/psirt/FG-IR-26-139
- Gentoo: https://bugs.gentoo.org/show_bug.cgi?id=CVE-2026-31431
- Juniper: https://supportportal.juniper.net/s/article/2026-05-Reference-Advisory-Status-of-Copy-Fail-vulnerability-on-Juniper-Products-CVE-2026-31431
- QNAP: https://www.qnap.com/zh-hk/security-advisory/qsa-26-16
Vulnerability Identifier
Source
- Ubuntu: https://ubuntu.com/security/CVE-2026-31431
- Debian: https://security-tracker.debian.org/tracker/CVE-2026-31431
- Red Hat: https://access.redhat.com/security/cve/cve-2026-31431
- SUSE: https://www.suse.com/security/cve/CVE-2026-31431.html
- Amazon: https://explore.alas.aws.amazon.com/CVE-2026-31431.html
- Arch: https://security.archlinux.org/CVE-2026-31431
- AlmaLinux: https://almalinux.org/blog/2026-05-01-cve-2026-31431-copy-fail/
- Cloudlinux: https://blog.cloudlinux.com/cve-2026-31431-copy-fail-mitigation-and-patches
- Fortinet: https://fortiguard.fortinet.com/psirt/FG-IR-26-139
- Gentoo: https://bugs.gentoo.org/show_bug.cgi?id=CVE-2026-31431
- Juniper: https://supportportal.juniper.net/s/article/2026-05-Reference-Advisory-Status-of-Copy-Fail-vulnerability-on-Juniper-Products-CVE-2026-31431
- QNAP: https://www.qnap.com/zh-hk/security-advisory/qsa-26-16
Related Link
- https://ubuntu.com/security/CVE-2026-31431
- https://security-tracker.debian.org/tracker/CVE-2026-31431
- https://access.redhat.com/security/cve/cve-2026-31431
- https://www.suse.com/security/cve/CVE-2026-31431.html
- https://explore.alas.aws.amazon.com/CVE-2026-31431.html
- https://security.archlinux.org/CVE-2026-31431
- https://almalinux.org/blog/2026-05-01-cve-2026-31431-copy-fail/
- https://blog.cloudlinux.com/cve-2026-31431-copy-fail-mitigation-and-patches
- https://bugs.gentoo.org/show_bug.cgi?id=CVE-2026-31431
- https://supportportal.juniper.net/s/article/2026-05-Reference-Advisory-Status-of-Copy-Fail-vulnerability-on-Juniper-Products-CVE-2026-31431
- https://www.qnap.com/zh-hk/security-advisory/qsa-26-16
- https://copy.fail/
- https://xint.io/blog/copy-fail-linux-distributions
- https://www.cisa.gov/news-events/alerts/2026/05/01/cisa-adds-one-known-exploited-vulnerability-catalog
- https://www.qnap.com/zh-hk/security-advisory/qsa-26-16
- https://fortiguard.fortinet.com/psirt/FG-IR-26-139
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