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PatchSiren cyber security CVE debrief

CVE-2026-55127 Microsoft CVE debrief

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-14T18:18:19.180Z and has not been modified since then. The NVD entry is currently Analyzed. This vulnerability, CVE-2026-55127, is a heap-based buffer overflow in Microsoft Office Word, which could allow an unauthorized attacker to execute code locally. The vulnerability has been assigned a CVSS score of 7.8 and a severity of HIGH. It affects various versions of Microsoft Office, including Office 2016, 2019, 2021, and 2024, as well as Microsoft 365 Apps. Users of these products should prioritize patching or updating to prevent exploitation. The CVE record and NVD detail provide information on the vulnerability, its impact, and affected products. However, the exact scope of affected systems and potential attack vectors are not detailed in the provided source corpus. To ensure protection, it is essential to apply patches or updates provided by Microsoft for the affected products and consider implementing compensating controls.

Vendor
Microsoft
Product
Microsoft 365 Apps for Enterprise
CVSS
HIGH 7.8
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 Word, particularly those using versions 2016, 2019, 2021, and 2024, as well as Microsoft 365 Apps, should be aware of this vulnerability.

Technical summary

A heap-based buffer overflow vulnerability exists in Microsoft Office Word, which could allow an unauthorized attacker to execute code locally. The vulnerability has been assigned a CVSS score of 7.8 and a severity of HIGH. It affects various versions of Microsoft Office, including Office 2016, 2019, 2021, and 2024, as well as Microsoft 365 Apps.

Defensive priority

High priority should be given to updating or patching vulnerable versions of Microsoft Office Word and Microsoft 365 Apps.

Recommended defensive actions

  • Apply patches or updates provided by Microsoft for the affected products.
  • Ensure that all users are aware of the vulnerability and the importance of applying patches.
  • Consider implementing compensating controls, such as restricting access to sensitive areas of the network.
  • Monitor systems for suspicious activity related to this vulnerability.
  • Perform regular inventory checks to ensure that all systems are up-to-date and patched.

Evidence notes

The CVE record and NVD detail provide information on the vulnerability, its impact, and affected products. However, the exact scope of affected systems and potential attack vectors are not detailed in the provided source corpus.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-55127 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-55127

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-55127 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-55127

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

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.