CVE-2026-13055: The `$_internalIndexKey` aggregation expression can be used by any authenticated user to crash a MongoDB serve

Routine

MEDIUM 6.5UPGRADE

CVE-2026-13055 is a medium-severity flaw (CVSS 6.5) affecting mongodb. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The `$_internalIndexKey` aggregation expression can be used by any authenticated user to crash a MongoDB server (mongod). The expression fails to handle compound wildcard index specifications, triggering an internal consistency check that aborts the server process. The user must be able to run an aggregation pipeline.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.4% (top 67%)
CISA exploited list	No
Weakness	CWE-617
Published	2026-07-22
Last modified	2026-10-24

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

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-22 20:16 UTCPublished CVE record published
2026-10-24 13:10 UTCUpdated Record last modified

mongodb mongodb UPGRADE

Affected: >= 7.0.0 and < 7.0.39 · >= 8.0.0 and < 8.0.28 · >= 8.2.0 and < 8.2.12 · >= 8.3.0 and < 8.3.7

Fixed in: 7.0.39, 8.0.28, 8.2.12, 8.3.7

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 7.0.39 (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.

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-2026-13055?

mongodb: upgrade to 7.0.39, 8.0.28, 8.2.12, 8.3.7. Exact commands for each OS are on this page.

Is CVE-2026-13055 being exploited?

CVE-2026-13055 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-2026-13055 affect?

CVE-2026-13055 affects mongodb. Severity is medium (CVSS 6.5). The `$_internalIndexKey` aggregation expression can be used by any authenticated user to crash a MongoDB server (mongod). The expression fails to handle compound wildcard index specifications, triggering an internal consistency check that a

How urgent is CVE-2026-13055?

Priority 31/100. No elevated risk signals yet.

Software pages

MongoDB vulnerabilities

Related CVEs

CVE-2026-13072 HIGH 8.1 UPGRADE When compute mode is enabled on a standalone mongod instance, insufficient validation of externally sourced BS
CVE-2026-13059 HIGH 8.1 UPGRADE An authenticated user with low privileges may be able to perform unauthorized reads and writes on data protect
CVE-2026-13078 HIGH 7.7 UPGRADE A vulnerability was discovered in MongoDB Server where the server-side MozJS scripting engine unconditionally
CVE-2026-13077 HIGH 7.1 UPGRADE A missing bounds check in the BSON CodeWScope element accessors allows an attacker to trigger an out-of-bounds
CVE-2026-13065 MEDIUM 6.5 UPGRADE A user with read-only privileges is able to craft an aggregation pipeline using the $linearFill window functio

References

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