CVE-2026-31431 is a recently disclosed Linux kernel vulnerability affecting the cryptographic subsystem specifically the algif_aead (AEAD socket interface) component of the kernel’s user space crypto API. In simple terms, the kernel incorrectly handles certain cryptographic data operations, which can be abused to corrupt memory.
Security impact – Risk Level- HIGH
kernel-level vulnerabilities can quickly escalate into full system compromise. For Oracle Linux environments especially those supporting databases and enterprise applications.
This vulnerability is particularly dangerous because:
1. Privilege escalation
- A local user can gain root (administrator) privileges on a vulnerable system.
2. Broad exposure
- This affects many Linux distributions and kernel versions since 2017.
3. Hard to detect
- Exploitation may:
- Leave no disk traces
- Evade file-integrity tools
4. Container escape risk
- Can potentially break out of container isolation environments.
Real-world risk scenarios
On Oracle Linux, an attacker could:
o Escalate privileges from a low-level user to root
o Compromise critical systems such as:
o Oracle Database servers
o Middleware and ERP platforms
o Cloud and container-based workloads
o Potentially bypass traditional security monitoring controls
Oracle Linux is directly affected because:
It is an enterprise Linux distribution based on the Linux kernel. The vulnerability impacts kernel-level code, not a distro-specific package
Specific implications for Oracle Linux:
· Vulnerable if running affected kernel versions (common in OL7, OL8, OL9 depending on patch level)
· Systems using:
o Crypto APIs (AF_ALG)
o Containers (Docker, Kubernetes on OL)
o Multi-user environments are at higher risk
· Included in affected enterprise distributions alongside: RHEL, Rocky, AlmaLinux, Ubuntu, SUSE, etc
Current status:
- No vendor-shipped kernel update has been broadly released yet across major enterprise distros, including Oracle Linux
- No broadly published Oracle Linux patch yet (as of now)
- Vendor patches expected soon (likely UEK/RHCK updates or Ksplice)
Recommended Interim Mitigation
Until an official patch is released, you can reduce risk by disabling the vulnerable interface (recommended across vendors)
Apply the restriction via grubby and reboot:
sudo grubby –update-kernel=ALL –args=”initcall_blacklist=algif_aead_init”
sudo reboot
After reboot, confirm the parameter is on the active kernel command line it should contain initcall_blacklist=algif_aead_init:
sudo grubby –info=ALL | grep initcall_blacklist
To revert after a patched kernel is installed:
sudo grubby –update-kernel=ALL –remove-args=”initcall_blacklist=algif_aead_init”
sudo reboot
This disables the vulnerable crypto interface and its low impact for most workloads.
Next Steps
o Monitor Oracle Linux security advisories and ULN updates
o Plan for rapid patch deployment once available
o Consider opening a Service Request (SR) with Oracle for environment-specific guidance.
References:
CERT-EU – High Vulnerability in the Linux Kernel (“Copy Fail”)
https://www.bugcrowd.com/blog/what-we-know-about-copy-fail-cve-2026-31431
Update 5/12 – Fix available, see Exadata 25.2 and 25.1 Update to Address CVE-2026-31431 – KB886658, Oracle Linux: How to Fix the CVE-2026-31431 – KB886346
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