CVE-2026-115823: Request Smuggling

Description

Starman versions before 0.4019 for Perl send response bodies for HEAD requests, desynchronizing responses on keep-alive connections. For a HEAD request Starman omits chunked framing but still writes the body returned by the application, on both the array and streaming response paths. Responses with a 1xx, 204 or 304 status also carry the body. On a keep-alive or pipelined connection the client reads those bytes as the start of the next response. A front-end proxy that reuses upstream connections may then pair responses with the wrong requests.

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Weakness Type (CWE)

CWE-444 CWE-444

References

Other References

https://github.com/miyagawa/Starman/commit/91c47c529cd1e100f938486896ea9083ec3ec7bf.patch https://metacpan.org/release/MIYAGAWA/Starman-0.4019/changes

Frequently Asked Questions

What is CVE-2026-115823? +

Starman versions before 0.4019 for Perl send response bodies for HEAD requests, desynchronizing responses on keep-alive connections. For a HEAD request Starman omits chunked framing but still writes the body returned by the application, on both the array and streaming response paths. Responses with a 1xx, 204 or 304 status also carry the body. On a keep-alive or pipelined connection the client reads those bytes as the start of the next response. A front-end proxy that reuses upstream connections may then pair responses with the wrong requests.

How do I check if I'm vulnerable to CVE-2026-115823? +

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.

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CVE-2026-115823