For CVE-2026-62433, the gap between CVSS 7.3 and EPSS 0.00263 is telling you something important: the CVSS captures theoretical severity while EPSS signals that weaponizing this class of bug is harder than the score implies. The actual exploitability hinges entirely on whether uninitialized kernel stack data can be coerced into userspace-accessible ioctl responses.
The vulnerability involves missing buffer validation in DM_OP ioctl handling—the code assumes callers provide required buffers without checking. This is a design decision that became a security failure, not a traditional buffer overflow. The key question that determines real impact: does the DM_OP ioctl response path actually serialize these partially-initialized structures back to callers? If the uninitialized data stays confined to kernel memory, the practical impact is information leakage to other kernel contexts at best, not privilege escalation to userspace.
The 'certain operations' language in the CVE description matters here. If the patch addressed a framework-level assumption rather than one isolated handler, this may represent a systemic design issue affecting multiple DM_OP operations. That changes the priority calculus: you should verify whether your kernel configuration or specific device-mapper targets expose broader attack surface than the single CVE suggests.
The CVSS 7.3 rating assumes the vulnerability is easily reachable and exploitable. For uninitialized stack access in kernel handlers, that assumption is questionable—you're at the mercy of whatever data happened to occupy those stack frames before your ioctl call. That unpredictability is both a mitigation and a complication.
Practical guidance: treat the CVSS as a theoretical upper bound, not a guaranteed severity. Prioritize understanding whether your specific DM_OP configuration has ioctl paths that serialize data back to userspace. If they don't, this vulnerability's real risk is low—but the design pattern it represents may surface again in adjacent code paths. The EPSS is telling you the kernel community already knows this is a 'hard to exploit' pattern; trust that signal.