Power Automate CVE-2026-77897

Requires a local, authenticated Windows account with at least low-level user privileges (PR:L) on a machine where Power Automate for Desktop or Power Automate agent for virtual desktops version before 2.71.115.26224 is installed. The AC:H metric indicates a high-complexity exploitation requirement - a specific environmental condition, timing window, or system state beyond the attacker's direct control must be met; the exact mechanism is not disclosed in available sources. Remote exploitation is not possible (AV:L). No user interaction from a second party is required (UI:N). Exploitation is limited to Windows endpoints running the affected Power Automate components; systems not running these products are unaffected.

The CVSS 7.0 base score (AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H) reflects a realistic but non-trivial local privilege escalation: attack vector is local, complexity is high, and a low-privileged local account is required. The high complexity metric (AC:H) suppresses the score from what would otherwise be a critical LPE, indicating that exploitation requires conditions beyond the attacker's direct control - likely a race window or specific system state. Full C:H/I:H/A:H impact reflects complete compromise of the local system once triggered. EPSS data is not available in the input. No KEV listing and no public POC reduce near-term risk further. Real-world risk is moderate: this is a meaningful LPE for threat actors who already have local foothold on a Windows machine running Power Automate for Desktop, making it relevant in post-compromise lateral movement or privilege escalation chains. It is not remotely exploitable and unlikely to be mass-automated. The AC:H constraint is the primary limiting factor - the precise triggering mechanism is not described in available sources.

A local attacker with a standard (low-privileged) Windows account on a machine running Power Automate for Desktop supplies a crafted relative path containing traversal sequences to a file operation handled by the elevated Power Automate agent service. Under the high-complexity condition required (such as a specific timing window or service state), the traversal succeeds and the agent writes attacker-controlled content into a privileged directory - for example, replacing a DLL in a system path - resulting in code execution at elevated privilege upon the next service or process invocation.