CVE-2026-82416FrankenPHP: Cross-request PHP session ID leak in worker mode when the session extension is a shared module

FrankenPHP is a modern application server for PHP. Prior to 1.12.5, FrankenPHP worker mode can retain PHP session state between requests when the session extension is loaded as a shared module and is unavailable through HAVE_PHP_SESSION at compile time. In this build configuration, frankenphp_reset_session_state() is compiled out, PS(id) can survive a request boundary, and a subsequent session_start() can ignore the new request's cookie because an identifier is already present. Under concurrent requests, session_id() can therefore return another client's identifier or a stale identifier from a previous request on the same worker thread, causing cross-user session exposure, possible session hijacking, and intermittent logout behavior. Builds with the session extension statically linked, including the official static binaries and Docker images, are not affected. This issue is fixed in version 1.12.5.

CVSS

7.7 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L

Weakness (CWE)

CWE-362, CWE-488

Known exploited

Not in CISA's KEV catalog

EPSS (exploitation in the next 30 days)

0.23% (percentile 13)

Assigned by

GitHub_M

NVD analysis

Deferred

Record last updated

Oct 13, 2026

First seen by InfoSec Signals

Oct 13, 2026

The CVE record on cve.org · NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.