VulnSocial

CVE-2026-21258Disclosure(microsoft / 365_apps)

LOWCVSS 5.5 · MEDIUM

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Track advisory updates for patch or workaround availability

Recommended action window: Monitor and triage in normal cycle

NVD description

Improper input validation in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.

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0.5/ 10 priority

Sources & remediation

Vendor / third-party advisories
Weakness type (CWE)
CWE-20CWE-125

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

NONE

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
  • office
  • office_long_term_servicing_channel

Threat summary

  • 1 mentions across 1 observed day

What's happening

  • Technical details provided in 1 signal
  • Disclosure: 1 classified signal
  • 1 total mentions across 1 day

Affected systems

Vendors
microsoft
Products
365_appsexcelofficeoffice_long_term_servicing_channeloffice_online_server

5 versions affected across 5 products

Deep dive

Activity timeline1 mentions / 1d
00111Mentions · 2026-02-10: 1Technical Details · 2026-02-10: 102-10
Signal classification1 categories
Disclosure
1100.0%
Referenced assets1 URL
By indicator
Full discourse1 post
  • CVE@CVEnew
    Disclosure

    CVE-2026-21258 Improper input validation in Microsoft Office Excel allows an unauthorized attacker to disclose information locally. https://www.cve.org/CVERecord?id=CVE-2026-21258

    Post summary

    The text briefly describes CVE-2026-21258 as an improper input validation flaw in Microsoft Office Excel that permits local information disclosure, without mentioning PoC, exploit tools, active exploitation, or patch information.

    00000195
    56.5K followersView on X
CPE platform detail13 entries

13 of 13 entries

PartVendorProductVersionTarget SWTarget HW
Appmicrosoft365_apps--x64
Appmicrosoft365_apps--x86
Appmicrosoftexcel2016-x64
Appmicrosoftexcel2016-x86
Appmicrosoftoffice2019-x64
Appmicrosoftoffice2019-x86
Appmicrosoftoffice_long_term_servicing_channel2021-x64
Appmicrosoftoffice_long_term_servicing_channel2021-x86
Appmicrosoftoffice_long_term_servicing_channel2021macos-
Appmicrosoftoffice_long_term_servicing_channel2024-x64
Appmicrosoftoffice_long_term_servicing_channel2024-x86
Appmicrosoftoffice_long_term_servicing_channel2024macos-
Appmicrosoftoffice_online_server---

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