CVE-2026-54998
Microsoft Exchange Online Elevation of Privilege Vulnerability
Vexday Risk Score
41Attention
SSVC decision (CISA)
Attend
PoC available → attend closely
Exploit maturity
Proof of concept
Popular PoC on GitHub (3 stars) — exploitation code widely available.
CVSS 8.8EPSS 0.6%KEV nãoPoC públicaNuclei —Metasploit —Patch referenciado
Lifecycle
02 Jul 2026Published on NVD
04 Jul 2026Public PoC
Weaponization speed
2 daysto first PoC
Weaponized quickly — attackers prioritized this vulnerability. Patch urgently.
Recommendation: Plan a near-term fix — a public PoC already exists.
Incorrect authorization in Microsoft Exchange Online allows an authorized attacker to elevate privileges over a network.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Affected products
Microsoft · Microsoft Exchange Onlinepublic PoCs found — 1
githubgithub.com/sentinel-aidefense/CVE-2026-54998-exp★ 3⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.