Microsoft PowerPoint CVE-2026-108453

Exploitation requires the victim to open or preview an attacker-crafted PowerPoint file in an affected Office build (Microsoft 365 Apps for Enterprise, Office LTSC 2021/2024, or the Office for Mac / LTSC for Mac 2021/2024 variants); the out-of-bounds read (CWE-125) is triggered during file parsing. The key limiting factor is mandatory user interaction (UI:R) - there is no server-side or zero-click path in the data - so the attack depends on social engineering to get the file opened. No special non-default configuration is indicated; any vulnerable, unpatched installation that opens the malicious document is exposed. Impact is read-only disclosure of memory, not code execution or data modification.

This is a moderate-priority information-disclosure flaw rather than a top-tier emergency. The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N, base 6.5) indicates a network-delivered, low-complexity, unauthenticated attack that nonetheless REQUIRES user interaction (UI:R) - the victim must open or preview a malicious PowerPoint file. Impact is confined to confidentiality (C:H), with no integrity or availability effect, consistent with a CWE-125 out-of-bounds read that leaks memory contents. No EPSS score, KEV listing, or POC was provided in the input, so there is no public exploit identified at time of analysis and no evidence of active exploitation; absence of these signals is not proof of safety but does argue against treating this as a wormable, mass-exploited bug. A vendor patch is confirmed available (MSRC update guide). The main tension in the data is severity-versus-reach: CVSS is 'Medium' and impact is read-only disclosure, yet the affected product family (Microsoft Office / PowerPoint) is extremely widely deployed, so even a medium-severity, interaction-gated bug warrants prompt patching in enterprise fleets. No SSVC decision values were supplied; exploitation automatability cannot be determined from the input.

An attacker crafts a malicious PowerPoint presentation that triggers an out-of-bounds read and emails or otherwise delivers it to a target. When the victim opens the file in a vulnerable Office/PowerPoint build, leaked heap or memory contents (potentially sensitive data or addresses usable to defeat ASLR) are disclosed to the attacker. No public exploit code was identified in the provided data, and successful exploitation hinges on the victim actively opening the attacker-supplied file (UI:R).