CVE-2025-30256VulnerabilityPublished 20 Aug 2025Updated 3 Nov 2025

CVE-2025-30256: Tenda AC6 V5.0 · Missing Release of Resource after Effective Lifetime

Affects Tenda AC6 V5.0Source CVE Database V5

Not known to be exploited · CVSS 8.6 High.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

8.6High

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 33% 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:C/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Changed
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: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
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 20 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 2026-10-25.

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
Tenda AC6 V5.0	Affected =02.03.01.110	Fixed in–

AI-suggested

Organizations should monitor Tenda's official channels for firmware updates addressing CVE-2025-30256 and apply patches immediately upon release. In the interim, network administrators should implement access control lists (ACLs) or firewall rules to restrict HTTP access to the management interface of Tenda AC6 routers from untrusted networks. Deploying network intrusion detection/prevention systems (IDS/IPS) with signatures or anomaly detection for abnormal HTTP header patterns may help detect or block exploit attempts. Segmentation of network zones to isolate critical devices and limiting exposure of router management interfaces to the internet can reduce attack surface. Regularly auditing device firmware versions and maintaining an inventory of affected hardware will aid in prioritizing remediation. Additionally, organizations should prepare incident response plans for potential denial of service events impacting network infrastructure.

Description

A denial of service vulnerability exists in the HTTP Header Parsing functionality of Tenda AC6 V5.0 V02.03.01.110. A specially crafted series of HTTP requests can lead to a reboot. An attacker can send multiple network packets to trigger this vulnerability.

Impact

For European organizations, the primary impact is disruption of network availability due to forced reboots of Tenda AC6 routers. This can lead to intermittent or prolonged loss of internet connectivity, affecting business continuity, remote work, and access to cloud services. Critical infrastructure sectors such as finance, healthcare, and manufacturing that rely on stable network environments may experience operational delays or outages. The vulnerability could also be leveraged as part of a larger attack chain to cause widespread denial of service in enterprise or ISP networks deploying these devices. Although confidentiality and integrity are not directly impacted, the loss of availability can have cascading effects on security monitoring, incident response, and service delivery. The lack of authentication or user interaction requirements increases the risk of automated exploitation attempts, especially in exposed network segments.

CWE-772Missing Release of Resource after Effective Lifetime (opens in a new tab)
Base weaknessLikelihood of exploit: High
The product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed.
Requirements · Language Selection
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Implementation
It is good practice to be responsible for freeing all resources you allocate and to be consistent with how and where you free resources in a function. If you allocate resources that you intend to free upon completion of the function, you must be sure to free the resources at all exit points for that function including…
Operation · Architecture and Design · Resource Limitation
Use resource-limiting settings provided by the operating system or environment. For example, when managing system resources in POSIX, setrlimit() can be used to set limits for certain types of resources, and getrlimit() can determine how many resources are available.
Attack patterns
HTTP DoS (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 3 Nov 2025, 19:07 UTC

WeaknessesCWE-772

Technical details

References

Community reviews

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