CVE-2023-0842: xml2js version 0.4.23 allows an external attacker to edit or add new properties to an object

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MEDIUM 5.3REMOTEDOWNGRADE

CVE-2023-0842 is a medium-severity flaw (CVSS 5.3) affecting xml2js. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

xml2js version 0.4.23 allows an external attacker to edit or add new properties to an object. This is possible because the application does not properly validate incoming JSON keys, thus allowing the __proto__ property to be edited.

Why this priority

Public exploit reference
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.4% (top 28%)
CISA exploited list	No
Weakness	CWE-1321
Published	2023-04-05
Last modified	2026-06-17

Publisher (CNA): Fluid Attacks · Vendor: xml2js project

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

Am I affected?

Timeline

2023-04-05 20:15 UTCPublished CVE record published
2026-06-17 05:26 UTCUpdated Record last modified

xml2js project xml2js DOWNGRADE

Affected: 0.4.23

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.4.23

1. Check installed version

apt-cache policy xml2js || rpm -q xml2js || xml2js --version

2. No fixed release: DOWNGRADE to a release before 0.4.23 (Debian / Ubuntu)

apt-cache madison xml2js sudo apt install xml2js=<VERSION_BEFORE_0.4.23> sudo apt-mark hold xml2js

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

dnf --showduplicates list xml2js sudo dnf downgrade xml2js-<VERSION_BEFORE_0.4.23> sudo dnf versionlock add xml2js

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-2023-0842?

xml2js: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2023-0842 being exploited?

CVE-2023-0842 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-2023-0842 affect?

CVE-2023-0842 affects xml2js. Severity is medium (CVSS 5.3). xml2js version 0.4.23 allows an external attacker to edit or add new properties to an object. This is possible because the application does not properly validate incoming JSON keys, thus allowing the __proto__ property to be edited.

How urgent is CVE-2023-0842?

Priority 47/100. Public exploit reference; Remotely exploitable, no login, no user action

References

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