CVE-2026-74438 Linux CVE debrief

Who should care

Users of Linux kernel should ensure their system is up-to-date to mitigate potential risks associated with this vulnerability. Linux kernel operators, platform administrators, vulnerability management teams, and security teams should review the vulnerability details and take necessary actions to secure their systems. This includes reviewing system configurations, monitoring for related security advisories, and ensuring compensating controls are in place for exposed systems.

Technical summary

The Linux kernel vulnerability CVE-2026-74438 has been resolved by removing the insecure and unused rng_alg. The removed code had multiple vulnerabilities, including a buffer overflow and failure to fill the entire buffer with cryptographic random bytes. This removal prevents potential security risks associated with the insecure code. The vulnerability was reported by Tianchu Chen and discovered by Atuin - Automated Vulnerability Discovery Engine. Users should ensure their Linux kernel is up-to-date to mitigate potential risks.

Defensive priority

This vulnerability affects Linux kernel and has been resolved by removing insecure and unused rng_alg. Users should ensure their Linux kernel is up-to-date.

Recommended defensive actions

• Ensure Linux kernel is up-to-date
• Review system for potential impacts of removed rng_alg
• Monitor system for any related security advisories
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The vulnerability was reported by Tianchu Chen and discovered by Atuin - Automated Vulnerability Discovery Engine. The affected code has been removed due to its insecure nature and lack of usage. There are no known users of this code, and it is only theoretically usable via the 'rng' algorithm type of AF_ALG. Userspace actually uses the actual Linux RNG (/dev/random etc) instead. The sun4i_ss_prng_seed() buffer overflow was a significant concern, and the code's removal prevents potential security risks. Defenders should verify that their Linux kernel is up-to-date and review system configurations for potential impacts of the removed rng_alg.

Official resources