Vulnerability in PHP Frankenphp
CVE-2026-24895
FrankenPHP is a modern application server for PHP. Prior to 1.11.2, FrankenPHP’s CGI path splitting logic improperly handles Unicode characters during case conversion. The logic computes the split index (for finding .php) on a lowercased copy of the request path but applies that byte index to the original path. Because strings.ToLower() in Go can increase the byte length of certain UTF-8 characters (e.g., Ⱥ expands when lowercased), the computed index may not align with the correct position in the original string. This results in an incorrect SCRIPT_NAME and SCRIPT_FILENAME, potentially causing FrankenPHP to execute a file other than the one intended by the URI. This vulnerability is fixed in 1.11.2.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.006 (50.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 50.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: +0.001
Affected products
- PHP Frankenphp — versions < 1.11.2
Weakness classification (CWE)
References
- github.com/php/frankenphp/security/advisories/GHSA-g966-83w7-6w38 (Exploit, Vendor Advisory)
- github.com/php/frankenphp/commit/04fdc0c1e8fde94e2c1ad86217e962c88d27c53e (Patch)
- github.com/php/frankenphp/releases/tag/v1.11.2 (Release Notes)
Frequently asked questions
- What is CVE-2026-24895?
- CVE-2026-24895 is a critical-severity vulnerability in PHP Frankenphp, classified under CWE-180. CVSS score: 9.8/10. Published 2026-02-12.
- How severe is CVE-2026-24895?
- Critical severity. CVSS v3 base score is 9.8 out of 10.