CVE-2026-31431: linux-azure-4.15, linux-azure-fips vulnerabilities
Affects Linux kernelSource GCVE Database
Exploited in the wild · KEV due 15 May 2026 · public exploit available (Metasploit) · fixed in 4.15.0-1201.216 : patch Linux kernel now.
Data as of 5 Nov 2026, 22:21 UTC
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
- Patch
- Available – fixed in 4.15.0-1201.216, 4.15.0-2110.116
Exploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 22 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
Exploited in the wildExploited: evidence found.
Listed in CISA KEV 21 days before disclosure
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
Added to CISA KEV (opens in a new tab)
exploitation confirmed
, 21 days before disclosure
KEV remediation due
US federal deadline
, 7 days before disclosure
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 5 Nov 2026.
What to do
Upgrade the Ubuntu to 4.15.0-1201.216 (linux-azure-4.15 package) or 4.15.0-2110.116 (linux-azure-fips package).
Patches and advisories
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu Pro 18.04 LTSlinux-azure-4.15pkg:deb/ubuntu/linux-azure-4.15?arch=source&distro=esm-infra/bionicOther threats | Affected
| Fixed in
|
Ubuntu Pro FIPS-updates 18.04 LTSlinux-azure-fipspkg:deb/ubuntu/linux-azure-fips?arch=source&distro=fips-updates/bionicOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
A vulnerability in the Linux kernel algif_aead module (CVE-2026-31431) allows improper handling of in-place cryptographic operations, known as Copy Fail. This flaw enables a local attacker to escalate privileges or potentially escape a container. The issue affects the linux-azure-4.15 kernel and related FIPS variants. Multiple security issues in cryptographic API and packet sockets subsystems were also addressed in the same update. Fixes are available and require system updates and reboot.
References
- ubuntu.com/security/notices/USN-8281-2 (opens in a new tab)
- ubuntu.com/security/CVE-2026-31431 (opens in a new tab)
- ubuntu.com/security/CVE-2026-31504 (opens in a new tab)
- ubuntu.com/security/CVE-2026-43033 (opens in a new tab)
- ubuntu.com/security/CVE-2026-43077 (opens in a new tab)
- ubuntu.com/security/CVE-2026-43078 (opens in a new tab)