CVE-2026-74578 Linux CVE debrief

Who should care

Linux kernel developers and maintainers, Linux distribution maintainers, and users of Linux-based systems should be aware of this vulnerability. They should assess exposure, prioritize remediation for systems using the affected kernel versions, and verify affected kernel versions. Additionally, security teams and vulnerability management teams should review the vulnerability and implement necessary mitigations.

Why it matters

The vulnerability in the Linux kernel's crypto: algif_skcipher allows an unprivileged user to recover the plaintext of a concurrent operation. Defenders should assess exposure and prioritize remediation for systems using the affected kernel versions.

• An unprivileged user may be able to recover the plaintext of a concurrent operation.
• The vulnerability requires verification of affected versions and remediation priority.
• Defenders should assess exposure and prioritize remediation for systems using the affected kernel versions.

Technical summary

The vulnerability is caused by the use of a shared IV in the async path of skcipher_recvmsg(). This allows an attacker to overwrite the IV and make the in-flight request run under an attacker-controlled IV, potentially allowing an unprivileged user to recover the plaintext of a concurrent operation. The issue affects the Linux kernel's crypto: algif_skcipher component. Defenders should assess exposure and prioritize remediation for systems using the affected kernel versions. The vulnerability requires verification of affected versions and remediation priority.

Defensive priority

High

Recommended defensive actions

• Review and apply the patches provided by the Linux kernel maintainers.
• Restrict access to the affected system to prevent exploitation.
• Monitor system logs for suspicious activity.
• Perform a thorough review of the system's configuration and assess exposure.
• Implement compensating controls for exposed systems while remediation is scheduled and verified.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.
• Review relevant monitoring, detection, and logs for exposed assets that need extra review.

Evidence notes

The vulnerability allows an unprivileged user to recover the plaintext of a concurrent operation. The issue is caused by the use of a shared IV in the async path of skcipher_recvmsg(). Evidence from the Linux kernel maintainers indicates that this vulnerability can be exploited in certain configurations. Defenders should verify affected kernel versions and assess exposure.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.