CVE-2026-31431: crypto: algif_aead - Revert to operating out-of-place

Overview

Severity
Medium (CVSS 5.5)
CVSS Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Exploit Status
Not Exploited
Patch Tuesday
2026-Apr
Released
2026-04-23
Last Updated
2026-05-05
EPSS Score
94.55% (percentile: 99.8%)

Detection & Weaponization (4 sources)

Maturity: Detection

  • Metasploit modules: Copy Fail AF_ALG + authencesn Page-Cache Write
  • Sigma rules: Linux AF_ALG Socket Creation - Kernel Crypto API Exploit Indicator, Authencesn Crypto Module Load via Modprobe - Copy-Fail Indicator
  • YARA rules: expl_copy_fail_cve_2026_31431.yar, SIGNATURE_BASE_EXPL_LNX_Copy_Fail_Artefacts_CVE_2026_31431_Apr26
  • GitHub PoC: 63 repositories

Affected Products (4)

Open Source Software

  • azl3 kernel 6.6.130.1-3 on Azure Linux 3.0
  • azl3 kernel 6.6.134.1-2 on Azure Linux 3.0
  • cbl2 kernel 5.15.202.1-1 on CBL Mariner 2.0

Other

  • 21300-17084

Revision History

  • 2026-04-23: Information published.
  • 2026-04-23: Information published.
  • 2026-04-29: Information published.
  • 2026-04-30: Information published.
  • 2026-05-01: Information published.
  • 2026-05-03: Information published.
  • 2026-05-04: Information published.
  • 2026-05-05: Information published.
  • 2026-05-05: Information published.