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PatchSiren cyber security CVE debrief

CVE-2009-3129 Microsoft CVE debrief

CVE-2009-3129 is a Microsoft Excel vulnerability described as a Featheader record memory corruption issue. CISA added it to the Known Exploited Vulnerabilities (KEV) catalog on 2022-03-03, indicating it is treated as actively exploited in the wild. The KEV record sets a remediation due date of 2022-03-24 and directs organizations to apply updates per vendor instructions.

Vendor
Microsoft
Product
Excel
CVSS
Unknown
CISA KEV
Listed
Original CVE published
2022-03-03
Original CVE updated
2022-03-03
Advisory published
2022-03-03
Advisory updated
2022-03-03

Who should care

Organizations that run Microsoft Excel, along with endpoint, patch management, and vulnerability response teams responsible for Microsoft Office update deployment.

Technical summary

The supplied sources identify the issue as a Microsoft Excel Featheader record memory corruption vulnerability. CISA’s KEV listing confirms the CVE is considered a known exploited vulnerability, but the provided corpus does not include a CVSS score, affected-version breakdown, or exploit mechanics beyond the record-corruption description.

Defensive priority

Immediate. CISA’s KEV inclusion is a strong signal to prioritize remediation ahead of routine patch cycles, especially for systems where Excel is installed and available to users.

Recommended defensive actions

  • Apply vendor-recommended updates as soon as possible for affected Microsoft Excel installations.
  • Track remediation against the CISA KEV due date of 2022-03-24 or sooner if your environment allows.
  • Verify patch deployment across endpoints and servers where Excel is present.
  • Escalate to incident response and vulnerability management workflows if any unpatched, exposed systems remain.
  • Record the asset scope and remediation status for audit and compliance tracking.

Evidence notes

This debrief is based only on the supplied CISA KEV metadata and the official CVE/NVD links provided in the corpus. The corpus confirms the CVE title, Microsoft Excel as the vendor/product, KEV listing status, date added, due date, and that known ransomware campaign use is unknown. It does not provide CVSS scoring, affected version ranges, exploit details, or Microsoft advisory text.

Sources and references

Verified primary and authoritative sources

  • CVE-2009-3129 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2009-3129

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

  • CVE-2009-3129 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2009-3129

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

  • CISA Known Exploited Vulnerabilities catalog

    Publisher, destination, and source semantics verified

    URL: https://www.cisa.gov/known-exploited-vulnerabilities-catalog

    Cybersecurity and Infrastructure Security Agency - Official CISA catalog of vulnerabilities known to be exploited in the wild.

Supplemental references

  • Source item URL

    Unverified legacy reference

    URL: https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

    cisa_kev

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.