Last Modified: Sep 30, 2026
Affected Product(s):
BIG-IP LTM
Known Affected Versions:
17.5.0, 17.5.1, 17.5.1.2, 17.5.1.3, 17.5.1.4, 17.5.1.5, 17.5.1.6, 17.5.1.8, 17.5.1.9
Opened: May 12, 2026 Severity: 3-Major
BIG-IP provides a Message Routing (MR) mechanism for HTTP/2 traffic to load balance each HTTP/2 stream individually. When enabled, this MR framework triggers the MR_EGRESS event before BIG-IP sends the request through the server-side stack. Execution of the HTTP::respond command fails with the error "Can't execute in the current context"
Any request triggering the command fails
- Virtual server is configured with HTTP MRF Router. - An iRule attached to the virtual server has the HTTP::respond command in the MR_EGRESS event - Traffic is passed across the virtual, triggering this HTTP::respond command
Depending on business logic, rewrite the iRule so the response is generated either earlier from a client-side / ingress-capable event like HTTP_REQUEST, or later from a server-side event like HTTP_REQUEST_RELEASE
None
When HTTP router is checked in virtual server configuration, BIG-IP triggers HTTP_REQUEST_SEND prior MR_EGRESS irule event on server side. These two events executed sequentially and uniformly like they would have different priority.