Advisoriesby IbisF5CVE-2026-63020
F5 BIG-IP: attacker could spoof error messages Impact: An attacker may
Fix: upgrade to 21.1.0.1 or later (4 fixed versions below)
A vulnerability exists in an undisclosed BIG-IP Configuration utility page that may allow an attacker to spoof error messages
Impact:
An attacker may trick authenticated BIG-IP users
into accessing malicious links and reflect a spoofed error message in
the victim's BIG-IP Configuration utility web browser session. This is a
control plane issue; there is no data plane exposure.
Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| BIG-IP Product | >= 21.1.0, < 21.1.0.1 | 21.1.0.1 |
| >= 21.0.0, < 21.0.0.3 | 21.0.0.3 | |
| >= 17.5.0, < 17.5.1.8 | 17.5.1.8 | |
| >= 17.1.0, < 17.1.3.4 | 17.1.3.4 |
Details and references
- CVSS 4.0
- CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Severity from
- the vendor (its own CVE record or advisory)
- Weakness
- CWE-451