SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityUndergoing Analysis

CVE-2026-18704

An issue in MongoDB Server's aggregation framework could allow an authenticated user with only read privileges to perform write operations against collections they should not be able to modify.

HIGH 7.1EPSS 0.21%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.21%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

An issue in MongoDB Server's aggregation framework could allow an authenticated user with only read privileges to perform write operations against collections they should not be able to modify. This is due to an internal-use aggregation stage being reachable by external clients without an appropriate authorization check on its embedded operations.

CVSS 4.0
7.1 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.21% probability · 12th percentile
CISA KEV
Not listed
Weakness
CWE-862
Source
cna@mongodb.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.