# CVE-2026-115865: Starlet denial of service via large Content-Length

Source: https://junglewise.ai/threats/cve-2026-115865-starlet-versions-before-0-33-for-perl-allow-a-request-declaring  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-30. Updated: 2026-10-30  
License: CC BY 4.0 with a link back

CVE-2026-115865 · Severity: info · Published 2026-10-30

Starlet is a Perl application server that handles HTTP requests. An attacker can send requests with an extremely large Content-Length header to exhaust a worker process's memory and crash it, causing service disruption. By sending multiple such requests, an attacker can repeatedly restart workers and degrade or halt the application.

Technologies: [Kazuho Starlet](https://junglewise.ai/threats/technologies/starlet). Vendors: [Kazuho](https://junglewise.ai/threats/vendors/kazuho).

## Quick answers

**Is CVE-2026-115865 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-115865 being exploited in the wild.

**How severe is CVE-2026-115865?** Informational severity, published 30 October 2026.

**Which products and versions are affected?** Kazuho Starlet before 0.33.

**Is there a fix for CVE-2026-115865?** Yes: fixed in Starlet 0.33. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-115865 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-115865?** Check whether you run Kazuho Starlet at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in Starlet 0.33

## Technical details

Starlet's request body reading loop passed the entire declared Content-Length value directly to sysread(), causing Perl to pre-allocate a buffer of that size before any data arrives. A request declaring a Content-Length larger than available memory causes an uncatchable out-of-memory error, killing the worker process. The fix limits each read to CHUNKSIZE pieces, matching the behavior of the chunked transfer encoding branch.

## Affected products

- Kazuho Starlet before 0.33

## Timeline

- 2026-10-30: disclosed

## References

- [https://cpan.org/modules](https://cpan.org/modules)
- [https://github.com/kazuho/Starlet/commit/598947ac620fd31b390335c683d79fa244770782.patch](https://github.com/kazuho/Starlet/commit/598947ac620fd31b390335c683d79fa244770782.patch)

## Related threats

- [Starlet memory exhaustion in chunked request decoding](https://junglewise.ai/threats/cve-2026-116128-starlet-versions-from-0-20-before-0-33-for-perl-allow-memory)
- [Starlet versions through 0.31 for Perl allows HTTP Request Smuggling via Improper Header Precedence. Starlet…](https://junglewise.ai/threats/cve-2026-40561-starlet-versions-through-0-31-for-perl-allows-http-request)