# GO-2026-5807 - Hysteria vulnerable to server crash when max_datagram_frame_size very small in github.com/apernet/hysteria

Source: https://junglewise.ai/threats/go-2026-5807-hysteria-vulnerable-to-server-crash-when-max-datagram-8f887c7f  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-07  
License: CC BY 4.0 with a link back

Severity: info · Published 2026-07-07

Hysteria vulnerable to server crash when max_datagram_frame_size very small in github.com/apernet/hysteria

Technologies: [github.com/apernet/hysteria (Go)](https://junglewise.ai/threats/technologies/github-com-apernet-hysteria). Vendors: [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is This vulnerability exploited in the wild?** No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

**How severe is This vulnerability?** Informational severity, published 7 July 2026.

**Which products and versions are affected?** github.com/apernet/hysteria (Go) SEMVER:introduced=0.

**Is there a fix for This vulnerability?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**Am I affected?** Check whether you run github.com/apernet/hysteria (Go) 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.

## Affected products

- github.com/apernet/hysteria (Go) SEMVER:introduced=0

## Related threats

- [GO-2026-5813 - Hysteria: http large header with sniff cause server DoS in github.com/apernet/hysteria](https://junglewise.ai/threats/go-2026-5813-hysteria-http-large-header-with-sniff-cause-server-dos-in-28a9ac9e)
- [apernet Hysteria Denial of Service in HTTP sniffing](https://junglewise.ai/threats/apernet-hysteria-denial-of-service-in-http-sniffing-904c3563)
- [apernet Hysteria server crash via small max_datagram_frame_size](https://junglewise.ai/threats/apernet-hysteria-server-crash-via-small-max-datagram-frame-size-34b2834d)