CVE-2026-77898
HIGHCVSS 7.5/10EPSS 0.47%
Last modified
CVE-2026-77898 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code over a network.. EPSS estimates a 0.47% chance of exploitation in the next 30 days.
Description
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code over a network.
Metrics
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | 365 Apps | All versions |
| Microsoft | Microsoft 365 | All versions |
| Microsoft | Office 2019 | All versions |
| Microsoft | Office 2021 | All versions |
| Microsoft | Office 2024 | All versions |
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-77898Patch, Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
What is CVE-2026-77898?
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code over a network.
How severe is CVE-2026-77898?
CVE-2026-77898 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.47% probability of exploitation in the next 30 days.
How do I fix CVE-2026-77898?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-77892No cwe for this issue in Windows Boot Manager allows an unau…6.8
- CVE-2026-77893Out-of-bounds read in Windows DHCP Server allows an unauthor…7.5
- CVE-2026-77894Concurrent execution using shared resource with improper syn…7
- CVE-2026-77895Out-of-bounds read in Windows DHCP Server allows an unauthor…7.5
- CVE-2026-77896Integer overflow or wraparound in Remote Desktop Client allo…6.5
- CVE-2026-77897Relative path traversal in Power Automate allows an authoriz…7
- CVE-2026-77899Use after free in Windows Security Center allows an authoriz…7
- CVE-2026-7790Uncontrolled Resource Consumption vulnerability in ninenines…7.5
- CVE-2026-77901Null pointer dereference in Microsoft Office Word allows an …8.8
- CVE-2026-77903Authentication bypass by spoofing in Microsoft Dataverse all…9
- CVE-2026-77904Heap-based buffer overflow in Windows Volume Manager Extensi…7.8
- CVE-2026-77905Use after free in Windows Management Instrumentation allows …7
Are you affected by CVE-2026-77898?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST