HPE NonStop CIPSAM CVE-2026-76660

Exploitation requires LOCAL access to an HPE NonStop system running the CIPSAM component at version T0693L02^BAU or earlier (AV:L), plus at least low-level privileges or an authenticated foothold (PR:L) - it is NOT remotely exploitable by an unauthenticated attacker. The attacker must be able to deliver malformed/crafted input to CIPSAM to trigger the out-of-bounds write; no end-user interaction is needed (UI:N) and attack complexity is low (AC:L). Limiting factors: the requirement for prior local access and credentials on a proprietary, access-controlled mission-critical platform significantly narrows the realistic attacker population compared to the raw 8.7 score. The description does not name a specific non-default configuration toggle, so the condition is the presence of a vulnerable CIPSAM version plus local privileged reachability.

The CVSS 3.1 base score of 8.7 (vector AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:H) is driven not by remote reach but by a changed scope combined with High integrity and availability impact - the attack vector is explicitly LOCAL and requires at least low-level privileges (PR:L), so this is an authenticated, local-access issue rather than a remotely-wormable one. No EPSS probability, CISA KEV entry, or public POC is present in the supplied intelligence, so there is no public exploit identified at time of analysis and no evidence of active exploitation. The signals are internally consistent (local vector + required privileges + no exploitation data), so this is best treated as a credible but NOT top-tier, internet-facing emergency: the high score reflects potential impact on a mission-critical platform once an attacker already has a foothold, not ease of initial access. Key caveat: the description is sparse (only 'out-of-bounds write that can corrupt buffer data') and does not confirm whether the integrity/availability impact equates to code execution or merely data/service corruption - verify exploitability details with the HPE advisory (hpesbns05148en_us). Prioritize patching on NonStop systems where untrusted or lower-privileged users have local/application access, but it does not demand the same emergency response as an unauthenticated network RCE.

An attacker who already holds a low-privileged account or application-level access on an HPE NonStop system supplies malformed input to the CIPSAM component, triggering an out-of-bounds write that corrupts buffer data. Because the CVSS scope is changed with High integrity and availability impact, successful corruption could affect components beyond CIPSAM's own privilege boundary, potentially crashing or manipulating dependent services. No public exploit code is available, so exploitation currently requires original research against a proprietary, niche platform.