How severe is CVE-2024-4023?

CVE-2024-4023 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability high.

Is CVE-2024-4023 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2024-4023?

CVE-2024-4023 affects Flatpress. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2024-4023?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2024-4023 have an EU (EUVD) identifier?

Yes. CVE-2024-4023 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-32589.

When was CVE-2024-4023 published?

CVE-2024-4023 was published on 2025-03-20 and last updated on 2026-06-17.

CVE-2024-4023

CVE-2024-4023 is a high-severity vulnerability in Flatpress with a CVSS 3.x base score of 8.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: High (CVSS 3.x base score 8.1)
EPSS exploit prediction: 1% (50th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-32589
Weakness: CWE-79
Affected product: Flatpress
Published: 2025-03-20
Last modified: 2026-06-17

Description

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 of the same origin.

Frequently asked questions

What is CVE-2024-4023?: 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 of the same origin.
How severe is CVE-2024-4023?: CVE-2024-4023 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability high.
Is CVE-2024-4023 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-4023?: CVE-2024-4023 affects Flatpress. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2024-4023?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2024-4023 have an EU (EUVD) identifier?: Yes. CVE-2024-4023 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-32589.
When was CVE-2024-4023 published?: CVE-2024-4023 was published on 2025-03-20 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:flatpress:flatpress:1.3:*:*:*:*:*:*:*

More vulnerabilities in Flatpress

CVE-2023-0947 — Critical (CVSS 9.8): Path Traversal in GitHub repository flatpressblog/flatpress prior to 1.3.
CVE-2022-4606 — Critical (CVSS 9.8): PHP Remote File Inclusion in GitHub repository flatpressblog/flatpress prior to 1.3.
CVE-2020-22761 — High (CVSS 8.8): Cross Site Request Forgery (CSRF) vulnerability in FlatPress 1.1 via the DeleteFile function in flat/admin.php.
CVE-2024-41290 — High (CVSS 8.1): FlatPress CMS v1.3.1 1.3 was discovered to use insecure methods to store authentication data via the cookie's component.
CVE-2023-1105 — High (CVSS 8.1): External Control of File Name or Path in GitHub repository flatpressblog/flatpress prior to 1.3.
CVE-2024-9847 — High (CVSS 8.0): FlatPress CMS version latest is vulnerable to Cross-Site Request Forgery (CSRF) attacks that allow an attacker to…

All CVEs affecting Flatpress →

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