Signal is active with 1 mentions in latest observed window
Recommended action window: Monitor and triage in normal cycle
NVD description
Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to elevate privileges locally.
Priority
LOW
Exploitation
NONE
PoC
NONE
Patch
NONE
Momentum
NONE
If you run products in this scope, you should treat this CVE as relevant to your environment.
5 versions affected across 5 products
CVE-2026-21259 Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to elevate privileges locally. https://www.cve.org/CVERecord?id=CVE-2026-21259
Post summary
This text announces CVE-2026-21259, a heap-based buffer overflow in Microsoft Office Excel that enables local privilege escalation, with no mention of PoC, exploitation, patch, or false‑positive claims.
11 of 11 entries
| Part | Vendor | Product | Version | Target SW | Target HW |
|---|---|---|---|---|---|
| App | microsoft | 365_apps | - | - | x64 |
| App | microsoft | 365_apps | - | - | x86 |
| App | microsoft | excel | 2016 | - | x64 |
| App | microsoft | excel | 2016 | - | x86 |
| App | microsoft | office | 2019 | - | x64 |
| App | microsoft | office | 2019 | - | x86 |
| App | microsoft | office_long_term_servicing_channel | 2021 | - | x64 |
| App | microsoft | office_long_term_servicing_channel | 2021 | - | x86 |
| App | microsoft | office_long_term_servicing_channel | 2024 | - | x64 |
| App | microsoft | office_long_term_servicing_channel | 2024 | - | x86 |
| App | microsoft | office_online_server | - | - | - |