[NEW] [high] Microsoft Exchange: Multiple vulnerabilities

highpublic exploitCVE-2026-54998 CVE-2026-55009 CVE-2026-55008 CVE-2026-55006 CVE-2026-55005

An attacker can exploit multiple vulnerabilities in Microsoft Exchange to execute arbitrary code, gain elevated permissions, or conduct spoofing attacks.

CSIRTS triage

vendor: Microsoft product: Exchange Remote code execution Privilege escalationOther

What: Multiple vulnerabilities in Microsoft Exchange can be exploited to execute arbitrary code and gain elevated permissions.
Who is affected: All deployments of Microsoft Exchange are affected.
Urgency: Remediation is high priority due to the potential for exploitation.
Action: Install the latest security patches for Microsoft Exchange.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: CERT-Bund (BSI) Security Advisories (DE · national-cert · site)
Severity: high
Published: 2026-07-15
Exploitation: Not in CISA KEV at last sync
Language: Machine-translated to English — verify against the original

Original advisory: https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-2326

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-549980.65% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 48% of all scored CVEs.
Moderate exploitation riskCVE-2026-550091.6% 30-day exploitation probability. Patch within normal cadence, watch for KEV listing. Riskier than 74% of all scored CVEs.
Low exploitation riskCVE-2026-550080.85% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 55% of all scored CVEs.
Low exploitation riskCVE-2026-550060.21% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 12% of all scored CVEs.
Low exploitation riskCVE-2026-550050.66% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 48% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-54998	coverage & exploitation status	NVD · CVE.org
CVE-2026-55009	coverage & exploitation status	NVD · CVE.org
CVE-2026-55008	coverage & exploitation status	NVD · CVE.org
CVE-2026-55006	coverage & exploitation status	NVD · CVE.org
CVE-2026-55005	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

Recent advisories for Microsoft Exchange

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

high[NEW] [high] Microsoft Azure, Copilot, Exchange, Surface: Multiple vulnerabilitiescert-bund · 2026-07-27
criticalCVE-2026-56191: Improper authentication in Microsoft Exchange Online allows an unauthorized attacker to perfor…nvd · 2026-07-24
unknownNCSC-2026-0234 [1.00] [M/H] Vulnerabilities fixed in Microsoft Exchangencsc-nl · 2026-07-14
highCVE-2026-55009: Deserialization of untrusted data in Microsoft Exchange Server allows an authorized attacker t…nvd · 2026-07-14
criticalCVE-2026-55008: Improper neutralization of input during web page generation ('cross-site scripting') in Micros…nvd · 2026-07-14
highCVE-2026-55006: Insufficient granularity of access control in Microsoft Exchange Server allows an authorized a…nvd · 2026-07-14