CVE-2026-82416: php frankenphp Race Condition

Vulnerability summary

CVE-2026-82416 is a high (CVSS 7.7) Race Condition vulnerability in php frankenphp. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 12.6% of scored vulnerabilities.

Timeline

1. 13-10-2026
   PublishedVulnerability first disclosed.
2. 13-10-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
• CWE-488Exposure of Data Element to Wrong SessionThe product does not sufficiently enforce boundaries between the states of different sessions, causing data to be provided to, or used by, the wrong session.