VulnerabilityPublished 23 Mar 2026

CVE-2025-15606: TP-Link Systems TD-W8961N v4.0 · Improper Input Validation

Affects TP-Link Systems TD-W8961N v4.0Source CVE Database V5

Not known to be exploited · CVSS 7.1 High : upgrade to V4_250925 soon.

Data as of 26 Oct 2026, 11:42 UTC

CVSS 4.0 base score

7.1High

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.
Patch: Available – fixed in V4_250925

CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Attack Vector: Adjacent
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: None
Vulnerable system availability: High
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Adjacent: The vulnerable system is bound to a protocol stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared proximity (e.g., Bluetooth, NFC, or IEEE 802.11) or logical network (e.g., local IP subnet), or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN within an administrative network zone).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: High: There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the Vulnerable System; 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 Vulnerable System (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).
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 23 Mar 2026
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

Upgrade TP-Link Systems TD-W8961N v4.0 to V4_250925.

Affected software

Product	Affected	Fixed in
TP-Link Systems Inc.TD-W8961N v4.0	Affected =0	Fixed in V4_250925

AI-suggested

Monitor TP-Link’s official channels for firmware updates or patches addressing CVE-2025-15606 and apply them promptly once available.
Restrict access to the router’s HTTP management interface by limiting it to trusted IP addresses or internal networks only, using firewall rules or access control lists.
Disable remote management over HTTP if not required, or switch to more secure management protocols such as HTTPS or SSH if supported.
Implement network segmentation to isolate critical devices and reduce exposure of vulnerable routers to untrusted networks.
Deploy intrusion detection or prevention systems (IDS/IPS) with custom signatures to detect and block malformed HTTP requests targeting the httpd service.
Regularly audit router configurations and logs for unusual access patterns or repeated crashes indicative of exploitation attempts.
Educate network administrators about the vulnerability and encourage proactive monitoring and incident response readiness.
Consider replacing affected devices with newer models that have improved security features if patching is not feasible.

Description

CVE-2025-15606 is a high-severity Denial-of-Service (DoS) vulnerability in the httpd component of TP-Link's TD-W8961N v4.0 router. It arises from improper input validation (CWE-20), allowing an attacker to send crafted HTTP requests that cause the httpd service to crash, resulting in service interruption. Exploitation requires no authentication or user interaction and can be performed remotely over the network. Although no known exploits are currently in the wild, the vulnerability poses a significant risk to availability. The CVSS 4.0 score is 7.1, reflecting its high impact and ease of exploitation. Organizations relying on this router model may experience network outages or degraded service. Mitigation involves applying vendor patches once available, restricting access to the device's management interface, and monitoring for unusual HTTP traffic patterns.

Impact

The primary impact of CVE-2025-15606 is a Denial-of-Service condition that disrupts the availability of the TP-Link TD-W8961N v4.0 router’s HTTP management interface. This can prevent administrators from accessing and managing the device remotely or locally via the web interface, potentially causing network outages or degraded performance if the router fails to recover automatically. For organizations relying on this router model for critical network connectivity or management, this could lead to operational downtime, loss of productivity, and increased support costs. While the vulnerability does not directly compromise confidentiality or integrity, the loss of availability can indirectly affect business continuity and incident response capabilities. The ease of exploitation and lack of required authentication increase the risk of automated attacks or widespread scanning by threat actors. Although no known exploits are currently in the wild, the vulnerability’s public disclosure may prompt attackers to develop exploits, increasing the threat over time.

Summary

CVE-2025-15606 identifies a Denial-of-Service vulnerability in the httpd (HTTP daemon) component of the TP-Link TD-W8961N version 4.0 router. The root cause is improper input validation (CWE-20), where the httpd service fails to properly sanitize incoming HTTP requests. An attacker can craft malicious requests that trigger a processing error within the httpd service, causing it to crash and thus interrupting the router's web management interface and potentially other dependent services. This vulnerability can be exploited remotely without any authentication or user interaction, making it accessible to unauthenticated attackers over the network. The impact is primarily on availability, as the router’s management service becomes unresponsive, leading to a Denial-of-Service condition. The CVSS 4.0 vector indicates low attack complexity, no privileges required, no user interaction, and no impact on confidentiality or integrity, but a high impact on availability. No patches or exploits are currently publicly available, but the vulnerability is published and assigned a high severity score of 7.1. The affected product is widely used in home and small office environments, which may expose many users to potential service disruptions if exploited.

CWE-20Improper Input Validation (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #18OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Attack Surface Reduction
Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build "recognizers" for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of…
Architecture and Design · Libraries or Frameworks
Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
Architecture and Design · Implementation · Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any…
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
Injection Prevention (opens in a new tab)
SQL Injection Prevention (opens in a new tab)
Injection Prevention in Java (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)
Attack patterns
Buffer Overflow via Environment Variables (opens in a new tab)
Server Side Include (SSI) Injection (opens in a new tab)
Cross Zone Scripting (opens in a new tab)
Command Line Execution through SQL Injection (opens in a new tab)
Object Relational Mapping Injection (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Mar 2026, 20:38 UTC

WeaknessesCWE-20

Technical details

References

Community reviews

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