VulnSocial

CVE-2026-55138Patch(microsoft / 365_apps)

LOWCVSS 5.5 · MEDIUM

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Patch microsoft 365_apps systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD description

Untrusted pointer dereference in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.

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1.0/ 10 priority

Sources & remediation

Vendor / third-party advisories
Weakness type (CWE)
CWE-822

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

NONE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • 365_apps
  • excel
  • microsoft_365
  • office_2019

Threat summary

  • Patch or workaround signal is available
  • 1 mentions across 1 observed day

What's happening

  • Patch or workaround mentioned in 1 signal
  • Technical details provided in 1 signal
  • 1 total mentions across 1 day

Affected systems

Vendors
microsoft
Products
365_appsexcelmicrosoft_365office_2019office_2021office_2024office_online_server

2 versions affected across 7 products

Deep dive

Activity timeline1 mentions / 1d
00111Mentions · 2026-07-15: 1Patch / Workaround · 2026-07-15: 1Technical Details · 2026-07-15: 107-15
Signal classification1 categories
Patch
1100.0%
Referenced assets1 URL
Full discourse1 post
  • Windows Forum@windowsforum
    Patch

    🪟 Excel’s “Medium” data leak still deserves a July patch: one malicious file interaction can expose sensitive info. Not exploited yet—an excellent time to keep it that way. https://windowsforum.com/threads/cve-2026-55138-patch-excel-data-exposure-with-july-updates.438705/?utm_source=x&utm_medium=social&utm_campaign=news_node84 #PatchManagement #OfficeSecurity #MicrosoftExcel #Cve202655138 https://t.co/DFHx13eFa7

    Post summary

    An unexploited CVE-2026-55138 causes a medium-grade data leak via a malicious Excel file interaction; a July patch is recommended.

    0000019
    1.2K followersView on X
CPE platform detail14 entries

14 of 14 entries

PartVendorProductVersionTarget SWTarget HW
Appmicrosoft365_apps--x64
Appmicrosoft365_apps--x86
Appmicrosoftexcel2016-x64
Appmicrosoftexcel2016-x86
Appmicrosoftmicrosoft_365-macos-
Appmicrosoftoffice_2019--x64
Appmicrosoftoffice_2019--x86
Appmicrosoftoffice_2021--x64
Appmicrosoftoffice_2021--x86
Appmicrosoftoffice_2021-macos-
Appmicrosoftoffice_2024--x64
Appmicrosoftoffice_2024--x86
Appmicrosoftoffice_2024-macos-
Appmicrosoftoffice_online_server---

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