CVE-2009-3939: The poll_mode_io file for the megaraid_sas driver in the Linux kernel 2.6.31.6 and earlier has world-writab...

Security readout for executives and security teams

CVE-2009-3939 is a Linux kernel permission flaw in the megaraid_sas storage driver. On affected systems, a local user could modify a world-writable driver control file and change the driver’s I/O mode. This is mainly a concern for older Linux systems using this RAID driver, especially multi-user servers. Exposure is likely limited to systems running affected older Linux kernels with the megaraid_sas driver present or loaded. Internet-facing exposure is not indicated. Risk is higher where untrusted local users, shared shell access, or compromised low-privilege accounts exist. Treat as a targeted legacy-infrastructure issue, not a broad emergency. Patch during normal vulnerability remediation, but accelerate for shared Linux servers or environments where low-privilege local access is common. Mitigation focus: Apply relevant vendor kernel updates from affected Linux distribution advisories.; Prioritize systems using megaraid_sas-backed storage or older 2.6-era kernels.; If no update path exists, consult vendor guidance for supported mitigation..

Prepared

Jun 28, 2026, 18:10 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.