2026-005: High Vulnerability in the Linux Kernel ("Copy Fail")

2026-005: High Vulnerability in the Linux Kernel ("Copy Fail") ↗ source

April 30, 2026 CERT-EU Advisory

Source: https://cert.europa.eu/publications/security-advisories/2026-005/

Summary

The vulnerability affects every mainstream Linux distributions shipping a kernel built since 2017. As of the date of this advisory, no distribution has shipped a fixed kernel package. The mainline fix was committed on 1 April 2026, but vendor updates are still pending across all major distributions. CERT-EU strongly recommends applying the interim mitigation immediately, prioritising Kubernetes nodes, and CI/CD runners exposed to untrusted workloads. The vulnerability CVE-2026-31431, with a CVSS score of 7.8, is a local privilege escalation flaw in the Linux kernel’s algif_aead module, the AEAD socket interface of the kernel’s userspace crypto API ( AF_ALG ).

News Coverage

Date	Source	Article
2026-08-26	Kaspersky Securelist	Exploits and vulnerabilities in Q2 2026 CVE-2026-31431

Articles from the monitored vendor research blogs and security news feeds that reference a CVE cited in this publication, or name the campaign it covers. Coverage begins when feed monitoring started; earlier articles are not indexed.

CVEs Referenced in This Publication

CVE	CVSS	Affected
CVE-2026-31431	7.8 High	Linux Kernel Linux Kernel contains an incorrect resource transfer between spheres vulnerability that could allow for privilege escalation.

Extracted from the publication text. Each CVE links to its tracked detail page.

Vendors Named in This Publication

Oracle 46 KEV Linux 31 KEV Red Hat 9 KEV Docker 1 KEV OpenSSL 1 KEV

Each vendor links to its Known Exploited Vulnerabilities catalog page. Only vendors that appear in the KEV catalog are listed, either because the publication cites one of their KEV entries or because it names them directly.