SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-20838

Office Server Document Converter V7.2MR4 and earlier and V7.1MR7 and earlier allows a remote unauthenticated attacker to conduct an XML External Entity (XXE) attack to cause a denial of service (DoS) condition by processing a specially crafted XML…

HIGH 7.5EPSS 1.52%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.52%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Office Server Document Converter V7.2MR4 and earlier and V7.1MR7 and earlier allows a remote unauthenticated attacker to conduct an XML External Entity (XXE) attack to cause a denial of service (DoS) condition by processing a specially crafted XML document.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
1.52% probability · 74th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-611
Affected
antennahouse/office server document converter
Source
vultures@jpcert.or.jp
EPSS trend
0%3%5%26 October 2026: 1.52%26 October 202626 October 2026

EPSS 1.5% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.