Linux Kernel EUVD-2026-108810

Signals conflict sharply between theoretical severity and real-world exposure. The CVSS 3.1 base score is 7.8 (HIGH) with C:H/I:H/A:H, which is justified: the flaw lets an unprivileged process drive FUTEX_WAKE_OP into an atomic read-modify-write on an arbitrary kernel virtual address, with the FUTEX_OP_CMP_* result acting as a read oracle - a primitive that can support local privilege escalation and kernel memory disclosure. However, the vector is AV:L/PR:L, so this is strictly a local, already-authenticated attack, not remotely reachable. The exploitability signals are all low: EPSS is 0.21% (10th percentile), there is no CISA KEV listing (not confirmed actively exploited), and no public exploit identified at time of analysis (the only references are the upstream kernel.org fix commits, not PoC code). The vuln.today Decision label is 'this_week', consistent with a serious-but-not-emergency local kernel bug. The decisive caveat is that exploitation is gated behind a narrow platform profile - RISC-V only, with CONFIG_RISCV_ISA_SUPM, hardware pointer masking, Sv57 paging and PMLEN=16 so tag bits overlap canonical kernel-address bits. This is a genuine kernel-memory-corruption primitive worth patching on the prescribed timeline, but the low EPSS and the RISC-V-specific, non-default configuration mean this is far from a widespread-exploitation priority; treat it as scheduled hardening for affected RISC-V fleets rather than an emergency.