CVE-2026-54998
Public exploit code is available. Proof-of-concept or working exploit code for CVE-2026-54998 is indexed in GitHub PoC. Expect opportunistic scanning and exploitation attempts — prioritize remediation even though it is not (yet) in the CISA KEV catalog.
A remote, authenticated attacker can exploit a vulnerability in Microsoft Exchange Online to elevate their privileges.
CSIRTS triage
- What
- A remote, authenticated attacker can exploit a vulnerability in Microsoft Exchange Online to elevate their privileges.
- Who is affected
- Authenticated users of Microsoft Exchange Online are affected.
- Urgency
- Remediation is high urgency due to the potential for privilege escalation.
- Action
- Apply the latest security updates for Microsoft Exchange Online.
AI-assisted analysis generated from the source advisory — verify against the original.
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Exploitation outlook
- Low exploitation risk0.63% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 46% of all EPSS-scored CVEs.
Exploit availability
Public exploit or proof-of-concept code for CVE-2026-54998 is indexed in these free datasets. Available exploit code raises real-world risk independent of the CVSS score.
- GitHub PoCPublic proof-of-concept repositories on GitHub reference this CVE.look it up ↗
Advisory coverage (3)
- high[NEW] [high] Microsoft Exchange Online: Vulnerability allows privilege escalationcert-bund · 2026-07-03
- highCVE-2026-54998: Incorrect authorization in Microsoft Exchange Online allows an authorized attacker to elevate …nvd · 2026-07-02
- highCVE-2026-54998: Microsoft Exchange Online Elevation of Privilege Vulnerabilitymsrc · 2026-07-02
External references
Embed the live status
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[](https://www.csirts.com/cve/CVE-2026-54998)