CVE-2025-46405VulnerabilityPublished 13 Aug 2025

CVE-2025-46405: F5 BIG-IP · Stack-based Buffer Overflow

Affects F5 BIG-IPSource CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 26 Oct 2026, 06:26 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 26% 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 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 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	Affected =17.1.0 =16.1.0 =15.1.0	Fixed in–

AI-suggested

1. Immediate mitigation should include disabling Network Access configuration on BIG-IP APM virtual servers if feasible until a patch is available. 2. Network segmentation and firewall rules should be implemented to restrict access to BIG-IP management and APM interfaces to trusted IP addresses only, minimizing exposure to untrusted networks. 3. Monitor network traffic and system logs for unusual or malformed traffic patterns that could trigger the vulnerability, enabling early detection of exploitation attempts. 4. Deploy rate limiting or traffic filtering on the perimeter to reduce the risk of DoS attacks targeting the TMM process. 5. Engage with F5 support and subscribe to their security advisories to obtain patches or official workarounds as soon as they are released. 6. Conduct thorough testing of patches in a controlled environment before deployment to avoid service disruptions. 7. Implement redundancy and failover mechanisms for BIG-IP devices to maintain service availability in case of TMM crashes. 8. Regularly update and audit BIG-IP configurations to ensure compliance with security best practices and minimize attack surface. 9. Train network and security teams on this specific vulnerability to improve incident response readiness.

Description

When Network Access is configured on a BIG-IP APM 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

For European organizations, the impact of CVE-2025-46405 can be substantial due to the widespread use of F5 BIG-IP devices in critical infrastructure, telecommunications, financial services, and government sectors. A successful exploitation can lead to denial of service on network access gateways, disrupting remote access, VPN services, and application delivery. This can cause operational downtime, loss of productivity, and potential financial losses. Additionally, disruption of BIG-IP services can affect security posture by disabling access control and inspection mechanisms, increasing exposure to other threats. Organizations that rely on BIG-IP for secure remote access (especially in the context of increased remote work) are particularly vulnerable. The vulnerability's ease of exploitation without authentication means attackers can launch DoS attacks from the internet, potentially targeting high-profile European entities or critical infrastructure. The lack of confidentiality or integrity impact reduces the risk of data breaches but does not diminish the operational risks associated with service outages. Given the strategic importance of network infrastructure in Europe, this vulnerability could be leveraged in targeted attacks or cause collateral damage during widespread scanning or exploitation attempts.

CWE-121Stack-based Buffer Overflow (opens in a new tab)
Variant weaknessLikelihood of exploit: HighCWE Top 25 (2025): #14
A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
Operation · Build and Compilation · Environment Hardening
Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index…
Architecture and Design
Use an abstraction library to abstract away risky APIs. Not a complete solution.
Implementation
Implement and perform bounds checking on input.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

my.f5.com/manage/s/article/K000151546 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 13 Aug 2025, 15:19 UTC

WeaknessesCWE-121

Technical details

References

Community reviews

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