4.2

CVE-2026-18703: mongodb Incorrect Authorization

CVSS: 4.2v3.1MediumAnalyzed
AliasesUBUNTU-CVE-2026-18703
Published 11-08-2026Last modified 11-08-2026
Open JSON

Vulnerability summary

CVE-2026-18703 is a medium (CVSS 4.2) Incorrect Authorization vulnerability in mongodb. EPSS estimates a 0.14% chance of exploitation in the next 30 days, higher than 3.3% of scored vulnerabilities.

Overall risk
17/100
0100
Low · default modelHow is this calculated?
CVSS score
4.2/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.14%
0%100%
Low · +0.03 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 11-08-2026
    PublishedVulnerability first disclosed.
  2. 11-08-2026
    Last modifiedVulnerability information updated.

Description

An issue in MongoDB Server could allow a party with a valid client certificate and a corresponding user account to authenticate using a certificate-based authentication method, even when an administrator has configured the server to restrict authentication to other mechanisms. This could allow authentication through a method the administrator intended to disable.

CVSS metrics

6 scores · 3 sources · 2 versions

EPSS trend

Probability

0.14%

Chance of exploitation in the next 30 days

Percentile

3%

Versus all other CVEs

30-day change

+0.03 pp

From 0.11% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.14%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Mongodb2 products
  • mongodb≥ 8.2.0, ≤ 8.2.12 | ≥ 8.3.0, < 8.3.8 | 9.0.0:alpha0 | 9.0.0:alpha1 | 9.1.0:alpha0
  • mongodb server≥ 8.3.0, < 8.3.8
Ubuntu1 product
  • mongodbAll versions (No fix recorded)

2 vendors · 3 products

References

3 links