CVE-2025-53737: Microsoft 365 Apps for Enterprise · Heap-based Buffer Overflow
Affects Microsoft 365 Apps for EnterpriseSource CVE Database V5
Not known to be exploited · CVSS 7.8 High.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 44% 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:CExploitation evidence
Disclosed: evidence found.
CVE published 12 Aug 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
| Product | Affected | Fixed in |
|---|---|---|
| Microsoft Microsoft 365 Apps for Enterprise | Affected
| Fixed in– |
AI-suggested
Until an official patch is released, organizations should implement targeted mitigations beyond generic advice: 1) Enforce strict email filtering and attachment scanning to block or quarantine suspicious Excel files, especially from unknown or untrusted sources. 2) Deploy application control policies to restrict execution of untrusted or unsigned macros and scripts within Excel. 3) Utilize Microsoft Defender Exploit Guard or similar endpoint protection features to detect and block heap overflow exploitation techniques. 4) Educate users about the risks of opening unsolicited Excel attachments and train them to recognize phishing attempts. 5) Implement network segmentation to limit lateral movement if a device is compromised. 6) Monitor endpoint behavior for anomalies indicative of exploitation attempts, such as unexpected process spawning or memory corruption alerts. 7) Maintain up-to-date backups and incident response plans to quickly recover from potential compromises. 8) Prepare for rapid deployment of the official patch once available by identifying and prioritizing vulnerable systems. These steps collectively reduce the attack surface and improve detection and response capabilities.
Description
Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code locally.