CVE-2021-34141: An incomplete string comparison in the numpy.core component in NumPy before 1.22.0 allows attackers to trigger

This week

MEDIUM 5.3REMOTEUPGRADEDOWNGRADE

CVE-2021-34141 is a medium-severity flaw (CVSS 5.3) affecting numpy, communications cloud native core policy. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An incomplete string comparison in the numpy.core component in NumPy before 1.22.0 allows attackers to trigger slightly incorrect copying by constructing specific string objects. NOTE: the vendor states that this reported code behavior is "completely harmless."

Why this priority

Public exploit reference
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	1.7% (top 23%)
CISA exploited list	No
Weakness	CWE-697
Published	2021-12-17
Last modified	2026-10-08

Publisher (CNA): MITRE · Vendor: numpy · oracle

Last updated 2026-10-08 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-12-17 19:15 UTCPublished CVE record published
2026-10-08 21:17 UTCUpdated Record last modified

numpy numpy UPGRADE

Affected: < 1.22.0

Fixed in: 1.22.0

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 1.22.0 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade numpy

Note

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

oracle communications cloud native core policy DOWNGRADE

Affected: 22.1.3

Fixed in: no fixed release known

Safe to downgrade to: a release before 22.1.3

1. Check installed version

apt-cache policy communications-cloud-native-core-policy || rpm -q communications-cloud-native-core-policy || communications-cloud-native-core-policy --version

2. No fixed release: DOWNGRADE to a release before 22.1.3 (Debian / Ubuntu)

apt-cache madison communications-cloud-native-core-policy sudo apt install communications-cloud-native-core-policy=<VERSION_BEFORE_22.1.3> sudo apt-mark hold communications-cloud-native-core-policy

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

dnf --showduplicates list communications-cloud-native-core-policy sudo dnf downgrade communications-cloud-native-core-policy-<VERSION_BEFORE_22.1.3> sudo dnf versionlock add communications-cloud-native-core-policy

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-2021-34141?

numpy: upgrade to 1.22.0; communications cloud native core policy: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-34141 being exploited?

CVE-2021-34141 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-2021-34141 affect?

CVE-2021-34141 affects numpy, communications cloud native core policy. Severity is medium (CVSS 5.3). An incomplete string comparison in the numpy.core component in NumPy before 1.22.0 allows attackers to trigger slightly incorrect copying by constructing specific string objects. NOTE: the vendor states that this reported code behavior is "

How urgent is CVE-2021-34141?

Priority 48/100. Public exploit reference; Remotely exploitable, no login, no user action

Software pages

Pandas and NumPy vulnerabilities

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References

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