CVE-2024-4023: A stored cross-site scripting (XSS) vulnerability exists in flatpressblog/flatpress version 1.3

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HIGH 8.1DOWNGRADE

CVE-2024-4023 is a high-severity flaw (CVSS 8.1) affecting flatpress. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A stored cross-site scripting (XSS) vulnerability exists in flatpressblog/flatpress version 1.3. When a user uploads a file with a `.xsig` extension and directly accesses this file, the server responds with a Content-type of application/octet-stream, leading to the file being processed as an HTML file. This allows an attacker to execute arbitrary JavaScript code, which can be used to steal user cookies, perform HTTP requests, and access content o

Why this priority

High severity
Public exploit reference

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

Risk facts

CVSS score	8.1 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.8% (top 43%)
CISA exploited list	No
Weakness	CWE-79
Published	2025-03-20
Last modified	2026-06-17

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

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

Am I affected?

Timeline

2025-03-20 10:15 UTCPublished CVE record published
2026-06-17 08:00 UTCUpdated Record last modified

flatpress flatpress DOWNGRADE

Affected: 1.3

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.3

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 1.3 (Debian / Ubuntu)

apt-cache madison flatpress sudo apt install flatpress=<VERSION_BEFORE_1.3> sudo apt-mark hold flatpress

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

dnf --showduplicates list flatpress sudo dnf downgrade flatpress-<VERSION_BEFORE_1.3> sudo dnf versionlock add flatpress

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-2024-4023?

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

Is CVE-2024-4023 being exploited?

CVE-2024-4023 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-2024-4023 affect?

CVE-2024-4023 affects flatpress. Severity is high (CVSS 8.1). A stored cross-site scripting (XSS) vulnerability exists in flatpressblog/flatpress version 1.3. When a user uploads a file with a `.xsig` extension and directly accesses this file, the server responds with a Content-type of application/oct

How urgent is CVE-2024-4023?

Priority 48/100. High severity; Public exploit reference

Related CVEs

CVE-2025-44108 MEDIUM 4.8 UPGRADE A stored Cross-Site Scripting (XSS) vulnerability exists in the administration panel of Flatpress CMS before 1
CVE-2025-29602 MEDIUM 6.1 UPGRADE flatpress 1.3.1 is vulnerable to Cross Site Scripting (XSS) in Administration area via Manage categories.
CVE-2025-25460 MEDIUM 4.8 DOWNGRADE A stored Cross-Site Scripting (XSS) vulnerability was identified in FlatPress 1.3.1 within the "Add Entry" fea
CVE-2024-9847 HIGH 8.0 UPGRADE FlatPress CMS version latest is vulnerable to Cross-Site Request Forgery (CSRF) attacks that allow an attacker
CVE-2024-9699 MEDIUM 5.4 UPGRADE A vulnerability in the file upload functionality of the FlatPress CMS admin panel (version latest) allows an a

References

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