🛡️ CVE-2026-26134 — 365-copilot

🟠 CVSS 7.8 — High ✅ No Known Exploit CWE-190 NVD
7.8
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Integer overflow or wraparound in Microsoft Office allows an authorized attacker to elevate privileges locally.

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

Weakness class

CVE-2026-26134 is classified as CWE-190: Integer Overflow or Wraparound. Arithmetic produces a value too large for its type and wraps around, so a later size or bounds check passes when it should not.

Affected software

CVE-2026-26134 is recorded against 2 packages.

  • 365-copilot (fixed in 16.0.19822.20000)
  • office (fixed in 16.0.19822.20000)

Timeline and source

Published on 10 March 2026 and last revised on 17 June 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

msrc.microsoft.com

Details

Severity HIGH
CVSS Score 7.8
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE CWE-190
Public Exploit ✅ No
Source NVD
Published 2026-03-10
Updated 2026-08-11
Modified 2026-06-17
Fix URL N/A

Affected Packages

Software From version Fixed in
365-copilot — 16.0.19822.20000
office — 16.0.19822.20000

Similar Threats

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