F5 BIG-IP prior 17.1.3.2/17.5.1.6/21.0.0.2 Traffic Management Microkernel allocation of resources

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.3$0-$5k0.00

Summaryinfo

A vulnerability was found in F5 BIG-IP. It has been classified as critical. The impacted element is an unknown function of the component Traffic Management Microkernel. The manipulation leads to allocation of resources. This vulnerability is uniquely identified as CVE-2026-40423. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as critical, has been found in F5 BIG-IP. This issue affects an unknown code block of the component Traffic Management Microkernel. The manipulation with an unknown input leads to a allocation of resources vulnerability. Using CWE to declare the problem leads to CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. Impacted is availability. The summary by CVE is:

When a SIP profile 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 at my.f5.com. The identification of this vulnerability is CVE-2026-40423 since 05/01/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 05/24/2026). MITRE ATT&CK project uses the attack technique T1499 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 316110 (F5 Networks BIG-IP : BIG-IP SIP profile vulnerability (K000161023)), 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 21.0.0.2 eliminates this vulnerability.

The vulnerability is also documented in the databases at CNNVD (CNNVD-202605-3305), Tenable (316110) and CERT Bund (WID-SEC-2026-1532). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

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

Exploitinginfo

Class: Allocation of resources
CWE: CWE-770 / CWE-400 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 316110
Nessus Name: F5 Networks BIG-IP : BIG-IP SIP profile vulnerability (K000161023)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: BIG-IP 17.1.3.2/17.5.1.6/21.0.0.2

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: K000161023
Status: Confirmed

CVE: CVE-2026-40423 (🔒)
GCVE (CVE): GCVE-0-2026-40423
GCVE (VulDB): GCVE-100-363557
CERT Bund: WID-SEC-2026-1532 - F5 BIG-IP Produkte: Mehrere Schwachstellen
CNNVD: CNNVD-202605-3305 - F5 BIG-IP 安全漏洞

Entryinfo

Created: 05/13/2026 17:41
Updated: 05/24/2026 23:29
Changes: 05/13/2026 17:41 (75), 05/14/2026 16:14 (6), 05/17/2026 13:35 (7), 05/24/2026 23:29 (2)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you need the next level of professionalism?

Upgrade your account now!