PatchSiren cyber security CVE debrief
CVE-2026-54988 Microsoft CVE debrief
AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-14T17:17:06.310Z and has not been modified since then. The NVD entry is currently Analyzed. This out-of-bounds read vulnerability in Microsoft Office Excel allows an unauthorized attacker to disclose information locally, with a CVSS score of 6.1 and a severity of MEDIUM. Users of Microsoft Office Excel, particularly those with local access, should be aware of this vulnerability as it allows for information disclosure. The CVE record and NVD details indicate an out-of-bounds read vulnerability in Microsoft Office Excel.
- Vendor
- Microsoft
- Product
- Microsoft 365 Apps for Enterprise
- CVSS
- MEDIUM 6.1
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-07-14
- Original CVE updated
- 2026-07-16
- Advisory published
- 2026-07-14
- Advisory updated
- 2026-07-16
Who should care
Users of Microsoft Office Excel, particularly those with local access, should be aware of this vulnerability as it allows for information disclosure. This vulnerability requires local access and user interaction to exploit, making it a concern for those who use Excel in local environments.
Technical summary
CVE-2026-54988 is an out-of-bounds read vulnerability in Microsoft Office Excel. This vulnerability allows an unauthorized attacker to disclose information locally. The vulnerability has a CVSS score of 6.1 and a severity of MEDIUM. It requires local access and user interaction to exploit. Users of Microsoft Office Excel, particularly those with local access, should be aware of this vulnerability as it allows for information disclosure.
Defensive priority
Medium priority should be given to patching this vulnerability, especially in environments where local access to Excel is common.
Recommended defensive actions
- Apply the patch provided by Microsoft
- Ensure that only authorized personnel have local access to Microsoft Office Excel
- Monitor for any suspicious local activity on systems with Excel installed
- Review compensating controls for exposed systems while remediation is scheduled and verified
- Check relevant monitoring, detection, and logs for exposed assets that need extra review
Evidence notes
The CVE record and NVD details indicate an out-of-bounds read vulnerability in Microsoft Office Excel. The CVSS vector is CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H, indicating a medium severity vulnerability that allows for information disclosure. The vulnerability has a CVSS score of 6.1 and a severity of MEDIUM. It requires local access and user interaction to exploit.
Sources and references
Verified primary and authoritative sources
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CVE-2026-54988 CVE Program record
Publisher, destination, and source semantics verified
URL: https://www.cve.org/CVERecord?id=CVE-2026-54988
CVE Program - Official CVE Program record with source-provided CVE metadata.
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CVE-2026-54988 NVD vulnerability detail
Publisher, destination, and source semantics verified
URL: https://nvd.nist.gov/vuln/detail/CVE-2026-54988
NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.
Supplemental references
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Mitigation or vendor reference
Unverified legacy reference
URL: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-54988
[email protected] - Patch, Vendor Advisory
Methodology and review provenance
AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.