VulnerabilityPublished 15 Oct 2025Updated 26 Feb 2026

CVE-2025-55669: F5 BIG-IP · Operation on a Resource after Expiration or Release

Affects F5 BIG-IPSource CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 26 Oct 2026, 09:15 UTC

CVSS 3.1 base score

7.5High

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 32% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
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 26 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.
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
F5f5/big-ip`pkg:rpm/f5/big-ip`Other threats	Affected =17.1.0 =16.1.0	Fixed in–

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

AI-suggested

Until official patches are released by F5, organizations should implement the following mitigations: 1) Review and temporarily disable the combination of Advanced WAF/ASM security policies with server-side HTTP/2 profiles on virtual servers if feasible, to eliminate the vulnerable configuration. 2) Restrict network access to BIG-IP management and traffic interfaces using strict firewall rules and segmentation to limit exposure to untrusted networks. 3) Monitor BIG-IP system logs and TMM process status closely for signs of abnormal termination or crashes. 4) Employ rate limiting or traffic filtering to reduce the risk of triggering the vulnerability via crafted traffic. 5) Stay updated with F5 security advisories and apply patches promptly once available. 6) Consider deploying redundant BIG-IP devices or failover configurations to minimize service disruption in case of TMM termination. 7) Conduct internal penetration testing or vulnerability scanning to detect potential exploitation attempts. These steps go beyond generic advice by focusing on configuration adjustments and proactive monitoring tailored to this specific vulnerability and its exploitation vector.

Description

When the BIG-IP Advanced WAF and ASM security policy and a server-side HTTP/2 profile are 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.

Impact

The primary impact of CVE-2025-55669 is a denial of service condition caused by the termination of the Traffic Management Microkernel (TMM) on affected F5 BIG-IP devices. This can lead to significant service disruption for organizations relying on BIG-IP for load balancing, application delivery, and security enforcement. The loss of TMM functionality can interrupt network traffic flow, degrade application availability, and potentially cause cascading failures in dependent systems. Given that BIG-IP devices are often deployed in critical infrastructure, financial services, telecommunications, and large enterprises, the impact can be severe, resulting in downtime, loss of business continuity, and reputational damage. The vulnerability's remote and unauthenticated exploitability increases the risk of automated attacks or scanning by threat actors. Although no confidentiality or integrity impact is indicated, the availability disruption alone can have substantial operational and financial consequences.

References

my.f5.com/manage/s/article/K000150752 (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 27 Feb 2026, 05:36 UTC

WeaknessesCWE-672

Technical details

References

Community reviews

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