F5 BIG-IP prior 17.1.3.2/17.5.1.6/21.0.0.1 Traffic Management Microkernel uninitialized pointer

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.3$0-$5k0.00

Summaryinfo

A vulnerability was found in F5 BIG-IP and classified as critical. The affected element is an unknown function of the component Traffic Management Microkernel. Executing a manipulation can lead to uninitialized pointer. This vulnerability is handled as CVE-2026-39458. The attack can be executed remotely. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in F5 BIG-IP. This vulnerability affects an unknown code of the component Traffic Management Microkernel. The manipulation with an unknown input leads to a uninitialized pointer vulnerability. The CWE definition for the vulnerability is CWE-824. The product accesses or uses a pointer that has not been initialized. As an impact it is known to affect availability. CVE summarizes:

When a BIG-IP DNS profile enabled with DNS cache is configured on a virtual server, undisclosed traffic can cause the Traffic Management Microkernel (TMM) to terminate.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

The advisory is shared for download at my.f5.com. This vulnerability was named CVE-2026-39458 since 05/01/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 05/24/2026).

The vulnerability scanner Nessus provides a plugin with the ID 316099 (F5 Networks BIG-IP : BIG-IP DNS Cache vulnerability (K000160945)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 17.1.3.2, 17.5.1.6 or 21.0.0.1 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (316099) and CERT Bund (WID-SEC-2026-1532). Once again VulDB remains the best source for vulnerability data.

Affected

  • F5 BIG-IP

Productinfo

Type

Vendor

Name

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.3

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.5
CNA Vector: 🔒

CVSSv2info

AVACAuCIA
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Uninitialized pointer
CWE: CWE-824 / CWE-908
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 316099
Nessus Name: F5 Networks BIG-IP : BIG-IP DNS Cache vulnerability (K000160945)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: BIG-IP 17.1.3.2/17.5.1.6/21.0.0.1

Timelineinfo

05/01/2026 CVE reserved
05/13/2026 +12 days Advisory disclosed
05/13/2026 +0 days VulDB entry created
05/24/2026 +11 days VulDB entry last update

Sourcesinfo

Vendor: f5.com

Advisory: K000160945
Status: Confirmed

CVE: CVE-2026-39458 (🔒)
GCVE (CVE): GCVE-0-2026-39458
GCVE (VulDB): GCVE-100-363556
CERT Bund: WID-SEC-2026-1532 - F5 BIG-IP Produkte: Mehrere Schwachstellen

Entryinfo

Created: 05/13/2026 17:41
Updated: 05/24/2026 23:39
Changes: 05/13/2026 17:41 (75), 05/17/2026 11:20 (7), 05/24/2026 23:39 (2)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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