Bug ID 2388333: BIG-IP terminates HTTP/2 with GOAWAY/PROTOCOL_ERROR when client sends empty initial SETTINGS frame

Last Modified: Jul 28, 2026

Affected Product(s):
BIG-IP LTM(all modules)

Known Affected Versions:
21.1.0, 21.1.0.1

Opened: Jul 09, 2026

Severity: 3-Major

Symptoms

The HTTP/2 protocol requires that an empty SETTINGS frame be sent as the first frame. When BIG-IP receives this empty initial SETTINGS frame, it incorrectly terminates the connection with a PROTOCOL_ERROR

Impact

Connection is immediately terminated, preventing the client from serving any requests

Conditions

- BIG-IP has a virtual server with an HTTP/2 profile - Client initiates an HTTP/2 connection and sends its initial SETTINGS frame with no settings

Workaround

None

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips