Last Modified: Jul 18, 2026
Affected Product(s):
BIG-IP ASM, Install/Upgrade
Known Affected Versions:
11.5.1, 11.5.1 hf1, 11.5.1 hf2, 11.5.1 hf3, 11.5.1 hf4, 11.5.1 hf5, 11.5.1 hf6, 11.5.1 hf7, 11.5.1 hf8, 11.5.1 hf9, 11.5.1 hf10, 11.5.1 hf11, 11.5.2, 11.5.2 hf1, 11.5.3, 11.5.3 hf1, 11.5.3 hf2, 11.5.4, 11.5.4 hf1, 11.5.4 hf2, 11.5.4 hf3, 11.5.4 hf4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 11.6.0, 11.6.0 hf1, 11.6.0 hf2, 11.6.0 hf3, 11.6.0 hf4, 11.6.0 hf5, 11.6.0 hf6, 11.6.0 hf7, 11.6.0 hf8, 11.6.1, 11.6.1 hf1, 11.6.1 hf2, 11.6.2, 11.6.2 hf1, 11.6.3, 11.6.3.1, 11.6.3.2, 11.6.3.3, 11.6.3.4, 11.6.4, 11.6.5, 11.6.5.1, 11.6.5.2, 11.6.5.3, 12.0.0, 12.0.0 hf1, 12.0.0 hf2, 12.0.0 hf3, 12.0.0 hf4
Fixed In:
12.1.0
Opened: Jun 26, 2015 Severity: 3-Major
After upgrading from 11.4.1 to 11.6.0, 11.6.1 or 12.0.0, you see a lot of "Illegal meta character in value" false positives on your XML content. The flagged character are valid within XML (<, >, /, :, etc.) and the affected URLs are associated with legitimate XML profiles via header-based content profiles. From the security event report, one can see that the invalid characters are for the global UNNAMED wildcard parameter and that the request is a multipart POST.
False positive violations could happen on the parameter enforcement (as it's not a parameter content but XML).
XML profile is assigned to the wildcard URL and having Header-Based Content profile.
N/A
Fixed a scenario when an XML profile is configured on the URL to not parse multipart root XML as form-data parameter, but only as XML.