CVE-2021-4279: A vulnerability has been found in Starcounter-Jack JSON-Patch up to 3.1.0 and classified as problematic

Q: How do I fix CVE-2021-4279?

json-patch: upgrade to 3.1.1. Exact commands for each OS are on this page.

Q: Is CVE-2021-4279 being exploited?

CVE-2021-4279 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-2021-4279 affect?

CVE-2021-4279 affects json-patch. Severity is medium (CVSS 6.3). A vulnerability has been found in Starcounter-Jack JSON-Patch up to 3.1.0 and classified as problematic. This vulnerability affects unknown code. The manipulation leads to improperly controlled modification of object prototype attributes ('

Q: How urgent is CVE-2021-4279?

Priority 44/100. Public exploit reference

This month

MEDIUM 6.3UPGRADE

CVE-2021-4279 is a medium-severity flaw (CVSS 6.3) affecting json-patch. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A vulnerability has been found in Starcounter-Jack JSON-Patch up to 3.1.0 and classified as problematic. This vulnerability affects unknown code. The manipulation leads to improperly controlled modification of object prototype attributes ('prototype pollution'). The attack can be initiated remotely. The exploit has been disclosed to the public and may be used. Upgrading to version 3.1.1 is able to address this issue. The name of the patch is 7ad6

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	6.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	1.2% (top 33%)
CISA exploited list	No
Weakness	CWE-1321
Published	2022-12-25
Last modified	2026-06-17

Publisher (CNA): VulDB · Vendor: starcounter-jack

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

Am I affected?

Timeline

2022-12-25 20:15 UTCPublished CVE record published
2026-06-17 04:19 UTCUpdated Record last modified

starcounter-jack json-patch UPGRADE

Affected: < 3.1.1

Fixed in: 3.1.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy json-patch || rpm -q json-patch || json-patch --version

2. UPGRADE to 3.1.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade json-patch

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade json-patch

Note

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

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-2021-4279?

json-patch: upgrade to 3.1.1. Exact commands for each OS are on this page.

Is CVE-2021-4279 being exploited?

CVE-2021-4279 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-2021-4279 affect?

CVE-2021-4279 affects json-patch. Severity is medium (CVSS 6.3). A vulnerability has been found in Starcounter-Jack JSON-Patch up to 3.1.0 and classified as problematic. This vulnerability affects unknown code. The manipulation leads to improperly controlled modification of object prototype attributes ('

How urgent is CVE-2021-4279?

Priority 44/100. Public exploit reference

References

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