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Fencer Intel
high 7.5

CVE-2026-18697 json

Improper Input Validation in MongoDB Aggregation Framework Allows Unauthenticated Denial of Service on mongos

published 2mo ago modified 17d ago also BIT-mongodb-2026-18697 , EUVD-2026-56910

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits
0
none known

Summary

An issue in MongoDB Server's aggregation framework could allow an unauthenticated party to cause a mongos (router) process to terminate unexpectedly by submitting a specially formed aggregation command. This could result in a denial of service, disrupting client connections routed through the affected mongos instance.

Patch / fix

  • bitnami mongodb 7.0.40, 8.0.29, 8.3.8, 9.0.2
  • MongoDB MongoDB Server 7.0.40, 8.0.29, 8.3.8

Is CVE-2026-18697 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
2mo ago

Exploit prediction

0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem package affected fixed in
bitnami mongodb
>=7.0.0, <7.0.40
>=8.0.0, <8.0.29
>=8.2.0, <8.3.8
>=9.0.0, <9.0.2
7.0.40
8.0.29
8.3.8
9.0.2

Affected products

  • MongoDB MongoDB Server

Classification

Weakness
Technology feeds

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.