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CVE-2025-59223VulnerabilityPublished Updated

CVE-2025-59223: Microsoft 365 Apps for Enterprise · Use After Free

Affects Microsoft 365 Apps for EnterpriseSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.3% chance of exploitation in 30 days – higher than 31% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 14 Oct 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

What to do

Affected software

ProductAffectedFixed in
Microsoft Microsoft 365 Apps for EnterpriseAffected
  • =16.0.1
Fixed in–

AI-suggested

Until an official patch is released, organizations should implement several specific mitigations to reduce risk. First, enforce strict email filtering and attachment scanning to block or quarantine suspicious Excel files, especially those from unknown or untrusted sources. Deploy endpoint protection solutions capable of detecting anomalous behavior related to use-after-free exploitation techniques. Educate users to avoid opening unsolicited or unexpected Excel attachments and to verify the source before enabling macros or content. Utilize Microsoft Defender Application Control or similar whitelisting technologies to restrict execution of unauthorized code. Employ network segmentation to limit lateral movement if a system is compromised. Monitor logs and alerts for unusual Excel process activity or crashes that could indicate exploitation attempts. Once Microsoft releases a patch, prioritize rapid deployment across all affected systems. Additionally, consider disabling legacy or unnecessary Office features that increase attack surface, such as macros or embedded objects, if not required.

Description

Use after free in Microsoft Office Excel allows an unauthorized attacker to execute code locally.

References

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