7.6

CVE-2026-18693: mongodb Out-of-bounds Write

CVSS: 7.6v3.1HighAnalyzed
AliasesUBUNTU-CVE-2026-18693
Published 11-08-2026Last modified 11-08-2026
Open JSON

Vulnerability summary

CVE-2026-18693 is a high (CVSS 7.6) Out-of-bounds Write vulnerability in mongodb. EPSS estimates a 0.34% chance of exploitation in the next 30 days, higher than 26.1% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.6/10
010
High · v3.1 (CVE.org)
EPSS score
0.34%
0%100%
Low · +0.10 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's handling of timeseries collections could allow an authenticated user with write privileges to cause an internal data structure to become inconsistent through certain document insertions. A subsequent insert into the affected bucket could then result in the server accessing memory outside its intended bounds, potentially causing a server crash (denial of service), exposure of limited memory contents, or memory corruption.

CVSS metrics

6 scores · 3 sources · 2 versions

EPSS trend

Probability

0.34%

Chance of exploitation in the next 30 days

Percentile

26%

Versus all other CVEs

30-day change

+0.10 pp

From 0.24% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.34%

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≥ 7.0.0, < 7.0.40 | ≥ 8.0.0, < 8.0.29 | ≥ 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 | ≥ 8.0, < 8.0.29 | ≥ 7.0, < 7.0.40
Ubuntu1 product
  • mongodbAll versions (No fix recorded)

2 vendors · 3 products

References

3 links