CVE-2025-55670VulnerabilityPublished 15 Oct 2025Updated 26 Feb 2026

CVE-2025-55670: F5 BIG-IP Next SPK · Unthrottled Resource Allocation

Affects F5 BIG-IP Next SPKSource CVE Database V5

Not known to be exploited · CVSS 6.5 Medium.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

6.5Medium

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 23% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
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: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 15 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 2026-10-26.

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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC 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

Affected software

Product	Affected	Fixed in
F5 BIG-IP Next SPK	Affected =1.7.0	Fixed in–

AI-suggested

To mitigate CVE-2025-55670, organizations should implement the following specific measures: 1) Monitor and analyze API call patterns to detect and alert on repeated or abnormal usage that could indicate exploitation attempts. 2) Apply rate limiting or throttling controls on the relevant API endpoints to prevent resource exhaustion from repeated calls. 3) Restrict network access to BIG-IP Next SPK management and API interfaces using segmentation, firewalls, and access control lists to limit exposure to trusted sources only. 4) Enforce the principle of least privilege by ensuring that accounts with API access have minimal permissions necessary for their function. 5) Stay informed on vendor advisories and apply patches or updates promptly once released by F5 to address this vulnerability. 6) Consider deploying redundancy and failover mechanisms for BIG-IP devices to maintain service availability in case of TMM termination. 7) Conduct regular security assessments and penetration testing focusing on API security and resource management. These measures go beyond generic advice by focusing on proactive detection, access restriction, and operational resilience tailored to the nature of this vulnerability.

Description

On BIG-IP Next CNF, BIG-IP Next SPK, and BIG-IP Next for Kubernetes systems, repeated undisclosed API calls can cause the Traffic Management Microkernel (TMM) to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Impact

The primary impact of CVE-2025-55670 is a denial of service condition caused by the termination of the Traffic Management Microkernel (TMM) on affected BIG-IP Next SPK systems. This disruption can lead to network traffic management failures, potentially causing outages or degraded performance for applications and services relying on these devices. Organizations that use BIG-IP Next SPK in their network infrastructure, especially for load balancing, security, and traffic routing, may experience service interruptions, impacting business continuity and user experience. While confidentiality and integrity remain unaffected, the availability impact can be significant in environments where BIG-IP devices are critical for operational uptime. The requirement for low privileges and network access lowers the barrier for exploitation, increasing the risk in exposed environments. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially if attackers develop exploits in the future. Overall, the vulnerability poses a moderate risk to organizations with BIG-IP Next SPK deployments, particularly those in sectors where network availability is crucial.

CWE-770Allocation of Resources Without Limits or Throttling (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #25
The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
Requirements
Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.
Architecture and Design
Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.
Architecture and Design
Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
OWASP ASVS 4.0.3
V8.1.4 (opens in a new tab)
V13.4.1 (opens in a new tab)
V11.1.4 (opens in a new tab)
Attack patterns
XML Ping of the Death (opens in a new tab)
Exponential Data Expansion (opens in a new tab)
Serialized Data Parameter Blowup (opens in a new tab)
Serialized Data with Nested Payloads (opens in a new tab)
Oversized Serialized Data Payloads (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

my.f5.com/manage/s/article/K000154614 (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 27 Feb 2026, 05:37 UTC

WeaknessesCWE-770

Technical details

References

Community reviews

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