CVE-2018-17175: In the marshmallow library before 2.15.1 and 3.x before 3.0.0b9 for Python, the schema "only" option treats an

Q: How do I fix CVE-2018-17175?

marshmallow: upgrade to 2.15.1; marshmallow: upgrade to 3.0.0b9. Exact commands for each OS are on this page.

Q: Is CVE-2018-17175 being exploited?

CVE-2018-17175 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2018-17175 affect?

CVE-2018-17175 affects marshmallow, marshmallow. Severity is medium (CVSS 5.3). In the marshmallow library before 2.15.1 and 3.x before 3.0.0b9 for Python, the schema "only" option treats an empty list as implying no "only" option, which allows a request that was intended to expose no fields to instead expose all field

Q: How urgent is CVE-2018-17175?

Priority 44/100. Remotely exploitable, no login, no user action

This month

MEDIUM 5.3REMOTEUPGRADEUPGRADE

CVE-2018-17175 is a medium-severity flaw (CVSS 5.3) affecting marshmallow, marshmallow. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In the marshmallow library before 2.15.1 and 3.x before 3.0.0b9 for Python, the schema "only" option treats an empty list as implying no "only" option, which allows a request that was intended to expose no fields to instead expose all fields (if the schema is being filtered dynamically using the "only" option, and there is a user role that produces an empty value for "only").

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.9% (top 20%)
CISA exploited list	No
Published	2018-09-18
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: marshmallow project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2018-09-18 17:29 UTCPublished CVE record published
2026-06-17 01:45 UTCUpdated Record last modified

marshmallow project marshmallow UPGRADE

Affected: < 2.15.1

Fixed in: 2.15.1

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 2.15.1 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade marshmallow

Note

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

marshmallow project marshmallow UPGRADE

Affected: >= 3.0 and < 3.0.0b9

Fixed in: 3.0.0b9

Safe to downgrade to: a release before 3.0

1. Check installed version

pip show marshmallow

2. UPGRADE to 3.0.0b9

pip install --upgrade "marshmallow>=3.0.0b9"

3. If no update is available yet, DOWNGRADE to a release before 3.0

pip index versions marshmallow pip install "marshmallow<3.0"

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-2018-17175?

marshmallow: upgrade to 2.15.1; marshmallow: upgrade to 3.0.0b9. Exact commands for each OS are on this page.

Is CVE-2018-17175 being exploited?

CVE-2018-17175 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-2018-17175 affect?

CVE-2018-17175 affects marshmallow, marshmallow. Severity is medium (CVSS 5.3). In the marshmallow library before 2.15.1 and 3.x before 3.0.0b9 for Python, the schema "only" option treats an empty list as implying no "only" option, which allows a request that was intended to expose no fields to instead expose all field

How urgent is CVE-2018-17175?

Priority 44/100. Remotely exploitable, no login, no user action

Software pages

Python vulnerabilities

References

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