CVE-2023-4879: Cross-site Scripting (XSS) - Stored in GitHub repository instantsoft/icms2 prior to 2.16.1.-git.

Q: How do I fix CVE-2023-4879?

instantcms: upgrade to 2.16.1. Exact commands for each OS are on this page.

Q: Is CVE-2023-4879 being exploited?

CVE-2023-4879 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-2023-4879 affect?

CVE-2023-4879 affects instantcms. Severity is medium (CVSS 4.8). Cross-site Scripting (XSS) - Stored in GitHub repository instantsoft/icms2 prior to 2.16.1.-git.

Q: How urgent is CVE-2023-4879?

Priority 30/100. Public exploit reference

Routine

MEDIUM 4.8UPGRADE

CVE-2023-4879 is a medium-severity flaw (CVSS 4.8) affecting instantcms. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Cross-site Scripting (XSS) - Stored in GitHub repository instantsoft/icms2 prior to 2.16.1.-git.

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	4.8 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	High
User interaction	Required
EPSS exploit chance	0.4% (top 66%)
CISA exploited list	No
Weakness	CWE-79
Published	2023-09-10
Last modified	2026-06-17

Publisher (CNA): huntr.dev · Vendor: instantcms

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

Am I affected?

Timeline

2023-09-10 18:15 UTCPublished CVE record published
2026-06-17 06:38 UTCUpdated Record last modified

instantcms instantcms UPGRADE

Affected: < 2.16.1

Fixed in: 2.16.1

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 2.16.1 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade instantcms

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-2023-4879?

instantcms: upgrade to 2.16.1. Exact commands for each OS are on this page.

Is CVE-2023-4879 being exploited?

CVE-2023-4879 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-2023-4879 affect?

CVE-2023-4879 affects instantcms. Severity is medium (CVSS 4.8). Cross-site Scripting (XSS) - Stored in GitHub repository instantsoft/icms2 prior to 2.16.1.-git.

How urgent is CVE-2023-4879?

Priority 30/100. Public exploit reference

Software pages

GitHub vulnerabilities · Git vulnerabilities

Related CVEs

CVE-2026-28281 HIGH 7.1 UPGRADE InstantCMS is a free and open source content management system
CVE-2025-59055 MEDIUM 4.7 UPGRADE InstantCMS is a free and open source content management system
CVE-2024-50348 MEDIUM 5.4 UPGRADE InstantCMS is a free and open source content management system
CVE-2024-31212 MEDIUM 6.7 DOWNGRADE InstantCMS is a free and open source content management system
CVE-2023-4878 MEDIUM 5.4 UPGRADE Server-Side Request Forgery (SSRF) in GitHub repository instantsoft/icms2 prior to 2.16.1-git.

References

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