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UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-18688

An issue in MongoDB Server's aggregation framework could allow an authenticated user to trigger an out-of-bounds memory read by providing a specially formed numeric parameter in a certain aggregation pipeline stage.

HIGH 7.1EPSS 0.40%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.40%). 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 to trigger an out-of-bounds memory read by providing a specially formed numeric parameter in a certain aggregation pipeline stage. This could result in a server crash (denial of service) and may potentially expose a limited amount of memory contents.

CVSS 4.0
7.1 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/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
0.40% probability · 34th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-125
Affected
mongodb/mongodb
Source
cna@mongodb.com
EPSS trend
0%3%5%26 October 2026: 0.40%26 October 202626 October 2026

EPSS 0.4% 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.

References

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