Microsoft 365 Apps For Enterprise vulnerabilities

CVE-2026-21511 [HIGH] CWE-502 CVE-2026-21511: Deserialization of untrusted data in Microsoft Office Outlook allows an unauthorized attacker to per Deserialization of untrusted data in Microsoft Office Outlook allows an unauthorized attacker to perform spoofing over a network.

CVE-2026-21259 [HIGH] CWE-122 CVE-2026-21259: Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to elevate priv Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to elevate privileges locally.

CVE-2026-21514 [HIGH] CWE-807 CVE-2026-21514: Reliance on untrusted inputs in a security decision in Microsoft Office Word allows an unauthorized Reliance on untrusted inputs in a security decision in Microsoft Office Word allows an unauthorized attacker to bypass a security feature locally.

CVE-2026-21258 [MEDIUM] CWE-20 CVE-2026-21258: Improper input validation in Microsoft Office Excel allows an unauthorized attacker to disclose info Improper input validation in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.

CVE-2026-21261 [MEDIUM] CWE-125 CVE-2026-21261: Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.

CVE-2026-21509 [HIGH] CWE-807 CVE-2026-21509: Reliance on untrusted inputs in a security decision in Microsoft Office allows an unauthorized attac Reliance on untrusted inputs in a security decision in Microsoft Office allows an unauthorized attacker to bypass a security feature locally.

CVE-2026-20946 [HIGH] CWE-125 CVE-2026-20946: Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to execute code locally Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to execute code locally.

CVE-2026-20953 [HIGH] CWE-416 CVE-2026-20953: Use after free in Microsoft Office allows an unauthorized attacker to execute code locally. Use after free in Microsoft Office allows an unauthorized attacker to execute code locally.

CVE-2026-20948 [HIGH] CWE-822 CVE-2026-20948: Untrusted pointer dereference in Microsoft Office Word allows an unauthorized attacker to execute co Untrusted pointer dereference in Microsoft Office Word allows an unauthorized attacker to execute code locally.

CVE-2026-20956 [HIGH] CWE-822 CVE-2026-20956: Untrusted pointer dereference in Microsoft Office Excel allows an unauthorized attacker to execute c Untrusted pointer dereference in Microsoft Office Excel allows an unauthorized attacker to execute code locally.

CVE-2026-20949 [HIGH] CWE-284 CVE-2026-20949: Improper access control in Microsoft Office Excel allows an unauthorized attacker to bypass a securi Improper access control in Microsoft Office Excel allows an unauthorized attacker to bypass a security feature locally.

CVE-2026-20955 [HIGH] CWE-822 CVE-2026-20955: Untrusted pointer dereference in Microsoft Office Excel allows an unauthorized attacker to execute c Untrusted pointer dereference in Microsoft Office Excel allows an unauthorized attacker to execute code locally.

CVE-2026-20950 [HIGH] CWE-416 CVE-2026-20950: Use after free in Microsoft Office Excel allows an unauthorized attacker to execute code locally. Use after free in Microsoft Office Excel allows an unauthorized attacker to execute code locally.

CVE-2026-20957 [HIGH] CWE-122 CVE-2026-20957: Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker to Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker to execute code locally.

CVE-2026-20944 [HIGH] CWE-125 CVE-2026-20944: Out-of-bounds read in Microsoft Office Word allows an unauthorized attacker to execute code locally. Out-of-bounds read in Microsoft Office Word allows an unauthorized attacker to execute code locally.

CVE-2026-20952 [HIGH] CWE-416 CVE-2026-20952: Use after free in Microsoft Office allows an unauthorized attacker to execute code locally. Use after free in Microsoft Office allows an unauthorized attacker to execute code locally.

CVE-2025-62562 [HIGH] CWE-416 CVE-2025-62562: Use after free in Microsoft Office Outlook allows an unauthorized attacker to execute code locally. Use after free in Microsoft Office Outlook allows an unauthorized attacker to execute code locally.

CVE-2025-62554 [HIGH] CWE-843 CVE-2025-62554: Access of resource using incompatible type ('type confusion') in Microsoft Office allows an unauthor Access of resource using incompatible type ('type confusion') in Microsoft Office allows an unauthorized attacker to execute code locally.

CVE-2025-62557 [HIGH] CWE-416 CVE-2025-62557: Use after free in Microsoft Office allows an unauthorized attacker to execute code locally. Use after free in Microsoft Office allows an unauthorized attacker to execute code locally.

CVE-2025-62555 [HIGH] CWE-416 CVE-2025-62555: Use after free in Microsoft Office Word allows an unauthorized attacker to execute code locally. Use after free in Microsoft Office Word allows an unauthorized attacker to execute code locally.