VulnSocial

CVE-2026-55121Patch(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

Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information locally.

microsoft CVEsBack to dashboard
1.0/ 10 priority

Sources & remediation

Patch / fix
Weakness type (CWE)
CWE-125

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
  • microsoft_365
  • office_2016
  • 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_appsmicrosoft_365office_2016office_2019office_2021office_2024sharepoint_server

3 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

    🪟 Microsoft patched an Office out-of-bounds read, but CVE-2026-55121’s official score says no data disclosure—just high availability impact. Patch anyway; CVSS drama can wait. https://windowsforum.com/threads/cve-2026-55121-office-fix-july-update-addresses-local-availability-risk.438875/?utm_source=x&utm_medium=social&utm_campaign=news_node84 #MicrosoftOffice #PatchManagement #SharepointSecurity #Cve202655121 https://t.co/nImj710IWX

    Post summary

    Microsoft has released a patch for CVE‑2026‑55121, an out‑of‑bounds read affecting Office that can degrade availability but does not expose data. Users should apply the patch promptly.

    0000039
    1.2K followersView on X
CPE platform detail16 entries

16 of 16 entries

PartVendorProductVersionTarget SWTarget HW
Appmicrosoft365_apps--x64
Appmicrosoft365_apps--x86
Appmicrosoftmicrosoft_365-macos-
Appmicrosoftoffice_2016--x64
Appmicrosoftoffice_2016--x86
Appmicrosoftoffice_2019--x64
Appmicrosoftoffice_2019--x86
Appmicrosoftoffice_2021--x64
Appmicrosoftoffice_2021--x86
Appmicrosoftoffice_2021-macos-
Appmicrosoftoffice_2024--x64
Appmicrosoftoffice_2024--x86
Appmicrosoftoffice_2024-macos-
Appmicrosoftsharepoint_server---
Appmicrosoftsharepoint_server2016--
Appmicrosoftsharepoint_server2019--

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