CVE-2026-55139

MEDIUMPre-NVD 5.55.5—
EchelonGraph scoreHIGH confidence

Score 5.5 from GitHub Security Advisory published 2026-07-14. the CNA's CVSS baseline 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:microsoft, epss, ghsa
Trending — 5 sources updated this week
5.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.5Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information locally.

CVSS v3
5.5
EG Score
5.5(high)
EPSS
28.3%
KEV
Not listed

Published

July 14, 2026

Last Modified

July 15, 2026

Advisory Details (1)

Auto-updated Jul 15, 2026
Patch available. Sources: microsoft.
microsoft Patch Available

Security Update Guide - Microsoft Security Response Center

Security Update Guide - Microsoft Security Response Center. Patch available via Microsoft Security Update

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55139

Vendor Advisories for CVE-2026-55139(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 8× in last 7d / 8× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-15 19:58 UTCEG score recompute
  2. 2026-07-15 19:58 UTCVendor advisory
  3. 2026-07-15 19:58 UTCGHSA enrichment
  4. 2026-07-15 16:57 UTCEPSS rescore
  5. 2026-07-15 16:57 UTCEPSS rescore
  6. 2026-07-14 17:43 UTCEG score recompute
  7. 2026-07-14 17:43 UTCVendor advisory
  8. 2026-07-14 17:40 UTCMITRE cvelistV5first tracked

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-55139?
CVE-2026-55139 is a medium vulnerability published on July 14, 2026. Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information locally.
When was CVE-2026-55139 disclosed?
CVE-2026-55139 was first published in the National Vulnerability Database on July 14, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55139 actively exploited?
CVE-2026-55139 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 28.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-55139?
CVE-2026-55139 has a CVSS v4.0 base score of 5.5 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-55139?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55139, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-55139

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