Widely deployed enterprise software; SSRF privilege escalation could compromise domains across many orgs.
CVE-2026-45504
SSRF in Exchange Server enables privilege escalation.
Is CVE-2026-45504 being exploited?
Not confirmed. CVE-2026-45504 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.85% probability of exploitation in the next 30 days.
How severe is CVE-2026-45504?
CVE-2026-45504 is rated High with a CVSS score of 8.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-45504?
Yes. A fix has been recorded for CVE-2026-45504. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-45504 affect?
CVE-2026-45504 affects Microsoft Exchange Server. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-45504?
Patch when available; harden SSRF paths; monitor privileged activity.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authenticated SSRF on Exchange Server can escalate privileges, enabling domain-wide access.
Immediate action required
- affected>= 15.01.0.0 and < 15.01.2507.071
- affected>= 15.02.0.0 and < 15.02.1544.043
- affected>= 15.02.0.0 and < 15.02.1748.048
- affected>= 15.02.0.0 and < 15.02.2562.045
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.