Bug ID 2359001: Portal access fails with the error 'ERROR: Fetching cookie failed' when large cookies are present.

Last Modified: Oct 16, 2026

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

Fixed In:
21.1.0.3, 17.5.1.10, 17.1.3.6

Opened: Jun 29, 2026

Severity: 3-Major

Symptoms

Portal access intermittently fails when the HTTP Analytics profile is enabled. Access logs display cookie fetch errors in RewritePlugin, such as: error rewrite - RewritePlugin.cpp:3290 (0x2005bd0): ERROR: Fetching cookie failed.

Impact

Connections face interruptions in service availability due to the inability to fetch backend cookies.

Conditions

Observed when large cookies are send by backends.

Workaround

None

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips