CVE-2026-20732Network attack vector

Error-message spoofing via undisclosed utility page

Published Feb 4, 2026 · Updated Feb 4, 2026

User-interface misrepresentation in F5 BIG-IP allows remote attackers to spoof error messages through the Configuration utility. F5 identifies only an undisclosed utility page and has not published the request field or rendering operation that accepts attacker-controlled content. Exploitation requires a user to interact with the response, and the documented consequence is limited to the integrity of displayed error information.

CVSS severity2.3
Low
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

User-interface misrepresentation in F5 BIG-IP allows remote attackers to spoof error messages through the Configuration utility. F5 identifies only an undisclosed utility page and has not published the request field or rendering operation that accepts attacker-controlled content. Exploitation requires a user to interact with the response, and the documented consequence is limited to the integrity of displayed error information.

The record

CVE
CVE-2026-20732
Published
Feb 4, 2026
Updated
Feb 4, 2026
Vendor
F5 Networks
Product
BIG-IP
Classifications
CWE-451, T1036
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 4, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=16.1.0 <*
  2. Affected versionversion=17.1.0 <17.1.3.1
  3. Affected versionversion=17.5.0 <17.5.1.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

F5 Networks · BIG-IPversion=16.1.0 <*; version=17.1.0 <17.1.3.1; version=17.5.0 <17.5.1.4

Published CVSS scores

4.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
2.3F5 NetworksCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
3.1F5 NetworksCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-451User Interface (UI) Misrepresentation of Critical Information
T1036Masquerading

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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