CVE-2026-46392
CVE-2026-46392 is a high-severity vulnerability with a CVSS 3.x base score of 8.7. 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-178.
Key facts
- Severity: High (CVSS 3.x base score 8.7)
- EPSS exploit prediction: 0% (13th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-34883
- Weakness: CWE-178
- Published:
- Last modified:
Description
HAX CMS helps manage microsite universe with PHP or NodeJs backends. Prior to version 26.0.0 of HAX CMS PHP, the `saveFile` endpoint validates upload extensions case-insensitively and writes the filename to disk verbatim, but the `.htaccess` rule that forces `Content-Disposition: attachment` on HTML files is case-sensitive. An HTML file uploaded with an uppercase extension (`.HTML`, `.Html`, `.HTM`) is still served as `text/html` but the forced-download header never applies, so the browser renders it inline and executes any embedded JavaScript in the HAXcms origin. This bypasses the mitigation shipped for CVE-2026-22704. Version 26.0.0 contains a fix.
Frequently asked questions
- What is CVE-2026-46392?
- HAX CMS helps manage microsite universe with PHP or NodeJs backends. Prior to version 26.0.0 of HAX CMS PHP, the `saveFile` endpoint validates upload extensions case-insensitively and writes the filename to disk verbatim, but the `.htaccess` rule that forces `Content-Disposition: attachment` on HTML files is case-sensitive. An HTML file uploaded with an uppercase extension (`.HTML`, `.Html`, `.HTM`) is still served as `text/html` but the forced-download header never applies, so the browser renders it inline and executes any embedded JavaScript in the HAXcms origin. This bypasses the mitigation shipped for CVE-2026-22704. Version 26.0.0 contains a fix.
- How severe is CVE-2026-46392?
- CVE-2026-46392 has a CVSS 3.x base score of 8.7, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
- Is CVE-2026-46392 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-46392?
- 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-2026-46392 have an EU (EUVD) identifier?
- Yes. CVE-2026-46392 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-34883.
- When was CVE-2026-46392 published?
- CVE-2026-46392 was published on 2026-06-05 and last updated on 2026-06-17.
References
Other CWE-178 vulnerabilities
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- CVE-2026-40453 — Critical (CVSS 9.9): The fix for CVE-2025-27636 added setLowerCase(true) to HttpHeaderFilterStrategy so that case-variant header names such…
- CVE-2026-47323 — Critical (CVSS 9.8): Camel-CXF and Camel-Knative Message Header Injection via Missing Inbound Filtering The CXF and Knative…
- CVE-2024-5699 — Critical (CVSS 9.8): In violation of spec, cookie prefixes such as `__Secure` were being ignored if they were not correctly capitalized - by…
- CVE-2023-3545 — Critical (CVSS 9.8): Improper sanitisation in `main/inc/lib/fileUpload.lib.php` in Chamilo LMS <= v1.11.20 on Windows and Apache…
- CVE-2022-29604 — Critical (CVSS 9.8): An issue was discovered in ONOS 2.5.1. An intent with an uppercase letter in a device ID shows the CORRUPT state, which…