NCSC-2026-0289 [1.00] [M/H] Vulnerabilities fixed in Microsoft Exchange Server

unknownCVE-2026-62910 CVE-2026-62912 CVE-2026-62913 CVE-2026-62914 CVE-2026-62915 CVE-2026-65813

Microsoft has fixed vulnerabilities in Exchange Server. A malicious actor can exploit the vulnerabilities to perform a Denial-of-Service attack, impersonate other users, escalate privileges, execute arbitrary code and/or access sensitive data. For successful exploitation, the malicious actor must have prior authentication.

CSIRTS triage

vendor: Microsoft product: Exchange Server Denial of service Authentication bypass Privilege escalation Remote code execution Information disclosure

What: Multiple vulnerabilities in Exchange Server allow authenticated actors to perform denial-of-service attacks, impersonate users, escalate privileges, execute arbitrary code, and access sensitive data.
Who is affected: Organizations running Exchange Server with authenticated access enabled.
Urgency: High; requires prior authentication but impacts core mail server functionality and includes code execution and privilege escalation vectors.
Action: Apply Microsoft's security updates for Exchange Server addressing CVE-2026-62910, CVE-2026-62911, CVE-2026-62912, CVE-2026-62913, CVE-2026-62914, CVE-2026-62915, and CVE-2026-65813.

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

⚡ Watch Exchange Server

Get an email when a new Exchange Server advisory drops — max one per day, one-click unsubscribe.

Details

Source: NCSC-NL Advisories (NL · national-cert · site)
Severity: unknown
Published: 2026-08-12
Exploitation: Not in CISA KEV at last sync
Language: Machine-translated to English — verify against the original

Original advisory: https://advisories.ncsc.nl/advisory?id=NCSC-2026-0289

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-2026-629100.68% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 49% of all EPSS-scored CVEs.
Moderate exploitation riskCVE-2026-629121.3% 30-day exploitation probability. Patch within normal cadence, watch for KEV listing. Riskier than 68% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-629130.62% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 47% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-629140.34% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 26% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-629150.48% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 40% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-658130.62% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 47% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-629110.72% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 51% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-62910	coverage & exploitation status	NVD · CVE.org
CVE-2026-62912	coverage & exploitation status	NVD · CVE.org
CVE-2026-62913	coverage & exploitation status	NVD · CVE.org
CVE-2026-62914	coverage & exploitation status	NVD · CVE.org
CVE-2026-62915	coverage & exploitation status	NVD · CVE.org
CVE-2026-65813	coverage & exploitation status	NVD · CVE.org
CVE-2026-62911	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 Server

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 Exchange Server: Multiple vulnerabilitiescert-bund · 2026-08-12
mediumCVE-2026-65813: Server-side request forgery (ssrf) in Microsoft Exchange Server allows an authorized attacker …nvd · 2026-08-11
mediumCVE-2026-62915: Missing authorization in Microsoft Exchange Server allows an authorized attacker to bypass a s…nvd · 2026-08-11
highCVE-2026-62914: Improper neutralization of input during web page generation ('cross-site scripting') in Micros…nvd · 2026-08-11
highCVE-2026-62913: Heap-based buffer overflow in Microsoft Exchange Server allows an authorized attacker to execu…nvd · 2026-08-11
mediumCVE-2026-62912: Deserialization of untrusted data in Microsoft Exchange Server allows an authorized attacker t…nvd · 2026-08-11