Skip to main content
VulnerabilityPublished Updated

CVE-2026-31431: linux-azure, linux-azure-5.4, linux-azure-fips vulnerabilities

Affects Linux kernelSource GCVE Database

0
Compare

Mentioned vulnerabilities

Exploited in the wild · KEV due 15 May 2026 · public exploit available (Metasploit) · 98% EPSS · fixed in 5.4.0-1163.169~18.04.1 : patch Linux kernel now.

Data as of 4 Nov 2026, 22:22 UTC

Exploitation

Actively exploited

High severity · No CVSS score from NVD or the CNA

KEV deadline
 US federal agencies must patch by this date; a sensible deadline for everyone else. Other KEV due dates
EPSS
98.1% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 5.4.0-1163.169~18.04.1, 5.4.0-1163.169, 5.4.0-1163.169+fips1

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

  1. Disclosed: evidence found.

    CVE published 22 May 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: evidence found.

    1 Metasploit module

  4. Exploited in the wild: evidence found.

    Listed in CISA KEV 21 days before disclosure

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

Timeline

  1. , 21 days before disclosure

  2. KEV remediation due

    US federal deadline

    , 7 days before disclosure

  3. CVE published

    on cve.org

    , t = 0

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 4 Nov 2026.

What to do

Upgrade the Ubuntu to 5.4.0-1163.169~18.04.1 (linux-azure-5.4 package) or 5.4.0-1163.169 (linux-azure package) or 5.4.0-1163.169+fips1 (linux-azure-fips package).

Affected software

ProductAffectedFixed in
Ubuntu Pro 20.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=esm-infra/focalOther threatsAffected
  • <5.4.0-1163.169
Fixed in
  • 5.4.0-1163.169
Ubuntu Pro FIPS-updates 20.04 LTSlinux-azure-fipspkg:deb/ubuntu/linux-azure-fips?arch=source&distro=fips-updates/focalOther threatsAffected
  • <5.4.0-1163.169+fips1
Fixed in
  • 5.4.0-1163.169+fips1
Ubuntu Pro 18.04 LTSlinux-azure-5.4pkg:deb/ubuntu/linux-azure-5.4?arch=source&distro=esm-infra/bionicOther threatsAffected
  • <5.4.0-1163.169~18.04.1
Fixed in
  • 5.4.0-1163.169~18.04.1

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

The Linux kernel algif_aead module contains a vulnerability known as Copy Fail, where in-place cryptographic operations are improperly handled. This flaw allows a local attacker to escalate privileges or potentially escape a container. Multiple other security issues affecting the Linux kernel's Cryptographic API, Packet sockets, and TLS protocol were also addressed. These vulnerabilities affect various linux-azure kernel versions and have been fixed in updated releases. A system reboot is required after applying the updates, and third-party kernel modules must be recompiled due to ABI changes.

References

Community reviews

Loading reviews…