CVE-2019-1204

CVE-2019-1204 is a medium-severity vulnerability in Microsoft Office with a CVSS 3.x base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Description

An elevation of privilege vulnerability exists when Microsoft Outlook initiates processing of incoming messages without sufficient validation of the formatting of the messages. An attacker who successfully exploited the vulnerability could attempt to force Outlook to load a local or remote message store (over SMB). To exploit the vulnerability, the attacker could send a specially crafted email to a victim. Outlook would then attempt to open a pre-configured message store contained in the email upon receipt of the email. This update addresses the vulnerability by ensuring Office fully validates incoming email formatting before processing message content.

Frequently asked questions

What is CVE-2019-1204?
An elevation of privilege vulnerability exists when Microsoft Outlook initiates processing of incoming messages without sufficient validation of the formatting of the messages. An attacker who successfully exploited the vulnerability could attempt to force Outlook to load a local or remote message store (over SMB). To exploit the vulnerability, the attacker could send a specially crafted email to a victim. Outlook would then attempt to open a pre-configured message store contained in the email upon receipt of the email. This update addresses the vulnerability by ensuring Office fully validates incoming email formatting before processing message content.
How severe is CVE-2019-1204?
CVE-2019-1204 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2019-1204 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (91st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-1204?
CVE-2019-1204 primarily affects Microsoft Office. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2019-1204?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2019-1204 published?
CVE-2019-1204 was published on 2019-08-14 and last updated on 2026-06-17.

References

Affected products (6)

More vulnerabilities in Microsoft Office

All CVEs affecting Microsoft Office →

Other CWE-20 (Improper Input Validation) vulnerabilities

Browse all CWE-20 (Improper Input Validation) vulnerabilities →