Vulnerability in PHP Frankenphp
CVE-2026-122233
FrankenPHP before 1.13.4 contains an information disclosure vulnerability in worker mode that fails to clear last HTTP stream response headers between requests, because the reset only happens in RSHUTDOWN, which worker requests skip. Later requests calling http_get_last_response_headers() can read headers fetched by earlier requests on the same worker thread, exposing other users' Set-Cookie or token headers from backend APIs.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.7 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.002 (14.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 14.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
The 30-day trend appears once there are two daily scores.
Affected products
Weakness classification (CWE)
References
- github.com/php/frankenphp/commit/3fade63bb1c1d246926ed8a00520015f94cdc819 (patch)
- github.com/php/frankenphp/releases/tag/v1.13.4 (release-notes)
- github.com/php/frankenphp/security/advisories/GHSA-pmvg-8483-mw84 (vendor-advisory)
- www.vulncheck.com/advisories/frankenphp-before-1.13.4-cross-request-response-he… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-122233?
- CVE-2026-122233 is a low-severity vulnerability in PHP Frankenphp, classified under CWE-488. CVSS score: 3.7/10. Published 2026-11-04.
- How severe is CVE-2026-122233?
- Low severity. CVSS v3 base score is 3.7 out of 10.