CVE-2026-18693: An issue in MongoDB Server's handling of timeseries collections could allow an authenticated user with write p

Routine

HIGH 7.6UPGRADEDOWNGRADE

CVE-2026-18693 is a high-severity flaw (CVSS 7.6) affecting mongodb, mongodb. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 corrupti

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	7.6 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.3% (top 74%)
CISA exploited list	No
Weakness	CWE-787
Published	2026-08-11
Last modified	2026-10-23

Publisher (CNA): MongoDB, Inc. · Vendor: mongodb

Last updated 2026-10-23 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-08-11 19:17 UTCPublished CVE record published
2026-10-23 21:10 UTCUpdated Record last modified

mongodb mongodb UPGRADE

Affected: >= 7.0.0 and < 7.0.40 · >= 8.0.0 and < 8.0.29 · >= 8.2.0 and <= 8.2.12 · >= 8.3.0 and < 8.3.8

Fixed in: 7.0.40, 8.0.29, 8.3.8

Safe to downgrade to: a release before 7.0.0

1. Check installed version

apt-cache policy mongodb || rpm -q mongodb || mongodb --version

2. UPGRADE to 7.0.40 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade mongodb

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mongodb

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 7.0.0 (Debian / Ubuntu)

apt-cache madison mongodb sudo apt install mongodb=<VERSION_BEFORE_7.0.0> sudo apt-mark hold mongodb

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list mongodb sudo dnf downgrade mongodb-<VERSION_BEFORE_7.0.0> sudo dnf versionlock add mongodb

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

mongodb mongodb DOWNGRADE

Affected: 9.0.0 alpha0 · 9.0.0 alpha1 · 9.1.0 alpha0

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.0.0

1. Check installed version

apt-cache policy mongodb || rpm -q mongodb || mongodb --version

2. No fixed release: DOWNGRADE to a release before 9.0.0 (Debian / Ubuntu)

apt-cache madison mongodb sudo apt install mongodb=<VERSION_BEFORE_9.0.0> sudo apt-mark hold mongodb

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list mongodb sudo dnf downgrade mongodb-<VERSION_BEFORE_9.0.0> sudo dnf versionlock add mongodb

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-18693?

mongodb: upgrade to 7.0.40, 8.0.29, 8.3.8; mongodb: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-18693 being exploited?

CVE-2026-18693 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-18693 affect?

CVE-2026-18693 affects mongodb, mongodb. Severity is high (CVSS 7.6). 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

How urgent is CVE-2026-18693?

Priority 33/100. High severity

Software pages

MongoDB vulnerabilities

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References

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