Potential Impact
A local attacker (e.g. any user with shell access) could potentially escalate their privileges to root, allowing them to read sensitive data, install malware, modify system files or pivot to other systems.
Immediate Mitigation
Since this is a kernel-level vulnerability, the immediate recommendation is to check with your distribution maintainer to see if a kernel patch has been released and patch as soon as possible. Several major distributions such as Debian, SUSE and Ubuntu have already released patches.
You must update your Linux distributions to a kernel version that includes mainline commit a664bf3d603d. This commit reverts the faulty in-place optimization and permanently neutralizes the attack
If you cannot patch the system immediately, consider disabling the vulnerable module by blacklisting the
algif_aead kernel module. This should not impact the vast majority of systems as the cryptography will fall back to standard userspace libraries.In addition, consider blocking sockets in containers: for untrusted workloads, CI runners, or Kubernetes clusters, block AF_ALG socket creation using seccomp profiles regardless of your patch state.
As with any change of this sort, it is always recommended to apply in a test scenario before deploying to production.
TrendAI Platform Monitoring and Defenses
As information about this LPE vulnerability is still evolving, TrendAI is closely monitoring and will continue to update as more information becomes available.
TrendAI customers can use the following as it develops to monitor and look for suspicious activity:
TrendAI Vision One Endpoint Security (and any solution that utilizes VSAPI detection)
- TrendAI has released a VSAPI pattern detection that detects known exploit code - this is detected as Trojan.Python.CVE202631431.A
- Public Exploit: Trojan.Linux.CVE202631431.A
TrendAI Vision One Container Security
- TrendAI customers can manage and enforce the recommended seccomp profiles using the Container Security module to prevent attackers from using this flaw as a cross-container or cross-tenant escape primitive.
- It is recommended to enable Container Runtime Rule (falco): TM-00000120 - (T1068) Setuid Binary Page Cache Manipulation
In addition, File Integrity Monitoring could be utilized to look for suspicious activity.
TrendAI Vision One XDR Threat Investigation
Monitor the Observed Attack Techniques (OAT) module for suspicious executions. Because the exploit typically targets setuid-root binaries (like /usr/bin/su or pkexec) to inject shellcode and open a root shell, any anomalous execution of these binaries by unprivileged users can trigger automated response actions.
Workbenches
- Page Cache Corruption Attack via Substitute User Binary
- Python Process Spawns Substitute User Binary with Privilege Escalation
- Suspicious Process Spawns Substitute User Binary with Privilege Escalation
- Suspicious Binary Spawns Substitute User Binary
Observed Attack Techniques
- Page Cache Corruption Attack via Substitute User Binary
- Python Process Spawns Substitute User Binary with Privilege Escalation
- Suspicious Binary Spawns Substitute User Binary
- Substitute User Binary Execution with Privilege Escalation from Non-Root Process
TrendAI Vision One Vulnerability Management
- Use the Cyber Risk Exposure Management (CREM) module to quickly discover and prioritize all Linux servers running vulnerable kernels compiled between 2017 and 2026.
TrendAI Vision One Forensics OSquery
- The following osquery can utilized in the Vision One Forensics module for collecting forensic endpoint information: V1 OSQuery CVE-2026-31431.txt (osquery contents in the text file)