Bug ID 2343841: Access Profiles reject HTTP requests that contain unencoded characters in the URI.

Last Modified: Jul 31, 2026

Affected Product(s):
BIG-IP None(all modules)

Known Affected Versions:
17.1.3.2, 17.1.3.4, 17.5.1.6, 17.5.1.8, 21.0.0, 21.0.0.1, 21.0.0.2, 21.0.0.3

Opened: Jun 19, 2026

Severity: 3-Major

Symptoms

Characters like backslash (\) in the URI cause HTTP request failures, triggering the error 'Access encountered an error (Operation not supported)' and resulting in TCP RST responses.

Impact

Requests with specific unencoded characters are rejected, disrupting application functionality.

Conditions

Requests containing unencoded special characters in the URI are generated by clients, such as browsers, curl, or custom applications.

Workaround

URI encoding using an iRule

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips