github.com/apernet/hysteria · Hysteria vulnerable to server crash when max_datagram_frame_size very small
Affects github.com/apernet/hysteriaSource GCVE Database
CVSS 7.5 High : upgrade to 2.9.2 soon.
Data as of 26 Jun 2026, 22:09 UTC
- Patch
- Available – fixed in 2.9.2
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HWhat to do
Upgrade github.com/apernet/hysteria to 2.9.2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Gogithub.com/apernet/hysteria | Affected
| Fixed in
|
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AI-suggested
If you cannot patch yet, avoid accepting clients that advertise very small max_datagram_frame_size values.
Description
An authenticated client can crash the Hysteria server by advertising a very small QUIC max_datagram_frame_size and triggering a UDP response. The server's fragmentation code does not handle cases where the UDP message header size exceeds the maximum datagram payload size, causing a slice bounds panic and server termination. This vulnerability affects Hysteria versions prior to 2.9.2.