VulnerabilityPublished 13 May 2026

CVE-2026-42063: F5 BIG-IP · Exposed Files or Directories

Affects F5 BIG-IPSource CVE Database V5

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Not known to be exploited · CVSS 4.9 Medium · fixed in 21.0.0.2 : update F5 BIG-IP when convenient.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

4.9Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 21% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 21.0.0.2, 17.5.1.6, 17.1.3.2

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 13 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade F5 BIG-IP to 21.0.0.2, 17.5.1.6 or 17.1.3.2.

Affected software

Product	Affected	Fixed in
F5BIG-IP	Affected >=21.0.0 <21.0.0.2 >=17.5.0 <17.5.1.6 >=17.1.0 <17.1.3.2 >=16.1.0	Fixed in 21.0.0.2 17.5.1.6 17.1.3.2
F5f5/big-ip`pkg:rpm/f5/big-ip`Other threats	Affected 16.1.0 – 21.0.0 4 affected builds	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

If you cannot patch yet, restrict access to the iControl SOAP interface to trusted administrators only and monitor for any unusual file access activity by privileged users.

Description

A vulnerability exists in iControl SOAP where an authenticated attacker with the Resource Administrator or Administrator role can download sensitive files. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Impact

An attacker with Resource Administrator or Administrator privileges can download sensitive files from the affected BIG-IP versions, potentially leading to unauthorized disclosure of sensitive information. There is no indication of impact on system integrity or availability. The vulnerability requires authenticated access with elevated privileges, limiting the scope of exploitation.

Summary

This vulnerability (CVE-2026-42063) in F5 BIG-IP involves improper access control in the iControl SOAP interface, permitting authenticated users with elevated roles (Resource Administrator or Administrator) to download sensitive files. The CVSS 3.1 base score is 4.9, reflecting a medium severity with network attack vector, low attack complexity, and high privileges required. The vulnerability does not affect confidentiality, integrity, or availability beyond unauthorized file disclosure. No official remediation or patch has been documented yet, and no known exploits have been reported.

CWE-552Files or Directories Accessible to External Parties (opens in a new tab)
Base weaknessOWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product makes files or directories accessible to unauthorized actors, even though they should not be.
Implementation · System Configuration · Operation
When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to disable public access.
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V12.5.1 (opens in a new tab)
V12.4.1 (opens in a new tab)
V8.3.8 (opens in a new tab)
Attack patterns
Collect Data from Common Resource Locations (opens in a new tab)
Probe System Files (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

my.f5.com/manage/s/article/K000160973 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 13 May 2026, 15:52 UTC

WeaknessesCWE-552

Technical details

References

Community reviews

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