VulnerabilityPublished 13 Aug 2025Updated 3 Nov 2025

CVE-2025-54500: F5 BIG-IP · Unthrottled Resource Allocation

Affects F5 BIG-IPSource CVE Database V5

Not known to be exploited · CVSS 5.3 Medium.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 3.1 base score

5.3Medium

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 42% 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:L

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

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: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 13 Aug 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 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

Affected software

Product	Affected	Fixed in
F5 BIG-IP	Affected 15.1.0 – 17.5.0 4 affected builds	Fixed in–

AI-suggested

Monitor network traffic for abnormal HTTP/2 behavior, specifically unusually high numbers of concurrent streams or malformed control frames, using advanced intrusion detection systems or network monitoring tools.
Implement rate limiting or throttling at the network edge or load balancer level to restrict the number of concurrent HTTP/2 streams accepted from a single client or IP address.
Deploy web application firewalls (WAFs) capable of inspecting HTTP/2 traffic and blocking malformed or suspicious control frames.
Segment and isolate BIG-IP management and control interfaces from untrusted networks to reduce exposure.
Maintain up-to-date inventories of BIG-IP versions in use and prioritize patching or upgrading to versions that address this vulnerability once available.
Engage with F5 support or security advisories regularly to obtain patches or recommended configuration changes.
Consider temporary disabling or limiting HTTP/2 support on BIG-IP devices if feasible and if the risk of DoS outweighs the benefits of HTTP/2 performance.
Conduct regular penetration testing and vulnerability assessments focused on HTTP/2 implementations to identify and remediate weaknesses proactively.

Description

An HTTP/2 implementation flaw allows a denial-of-service (DoS) that uses malformed HTTP/2 control frames in order to break the max concurrent streams limit (HTTP/2 MadeYouReset Attack). Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Impact

For European organizations, the primary impact of CVE-2025-54500 is the risk of denial-of-service attacks against critical network infrastructure that uses F5 BIG-IP devices. These devices are widely deployed in enterprise environments for load balancing, application delivery, and security functions. A successful attack could disrupt availability of web applications, internal services, and customer-facing portals, leading to operational downtime and potential financial losses. Sectors such as finance, telecommunications, government, and healthcare, which often rely on BIG-IP for high availability and security, could experience significant service interruptions. Additionally, the disruption could affect compliance with service-level agreements (SLAs) and regulatory requirements related to uptime and incident response. Although confidentiality and integrity are not directly impacted, the availability degradation could indirectly affect business operations and trust. The lack of authentication or user interaction requirements makes the attack feasible from remote locations, increasing the threat surface for European organizations with internet-facing BIG-IP deployments.

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

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 4 Nov 2025, 01:40 UTC

WeaknessesCWE-770

Technical details

References

Community reviews

Related threats