CVE-2026-122233 (CVSS 3.7)

Description

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.

Is your site exposed to CVE-2026-122233?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

3.7

LOW

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS — Exploit Prediction

0.0023

Probability of exploitation

0.14%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-488 CWE-488

References

Other References

https://github.com/php/frankenphp/commit/3fade63bb1c1d246926ed8a00520015f94cdc819 https://github.com/php/frankenphp/releases/tag/v1.13.4 https://github.com/php/frankenphp/security/advisories/GHSA-pmvg-8483-mw84 https://www.vulncheck.com/advisories/frankenphp-before-1.13.4-cross-request-response-header-leak-in-worker-mode

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 3.7 (LOW).

How severe is CVE-2026-122233? +

CVE-2026-122233 has a CVSS v3.1 score of 3.7 out of 10, rated LOW. This is a low-severity vulnerability with limited impact. The EPSS score is 0.0023, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-122233? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-82806

Exposure of data element to wrong session vulnerability in Apache APISIX. This issue affects Apache APISIX: from 2.3.0 before 3.7.0. …

CVE-2026-112921

Robots::Validate versions from 0.4.3 before 0.4.10 for Perl report clients as imposter robots when User-Agent matcher state carries over from …

CVE-2026-111245

After a successful WS-Security UsernameToken authentication, the caller identity stays associated with the worker thread once the request completes when …

CVE-2026-97888

The embedded HTTP server does not clear the security identity established during a request before its worker thread handles the …

CVE-2026-111242

When MicroProfile JWT authentication is used for servlets that declare a run-as identity, the security state established for a request …

CVE-2026-82367

Exposure of Data Element to Wrong Session vulnerability in ash-project ash_graphql can deliver one subscription's resolved records to a different …