VulnerabilityPublished 14 Jan 2026

CVE-2025-67835: Paessler PRTG Network Monitor · CVE-2025-67835 is a medium-severity

Source CVE Database V5

Not known to be exploited · CVSS 6.5 Medium.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

6.5Medium

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 35% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Affects: Paessler PRTG Network Monitor before 25.4.114

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
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: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
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 14 Jan 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

AI-suggested

Restrict access to the Notification Contacts functionality to only trusted and necessary users, employing the principle of least privilege.
Monitor logs and system behavior for unusual activity related to Notification Contacts usage that could indicate attempts to exploit the vulnerability.
Implement strong authentication mechanisms, including multi-factor authentication, to reduce the risk of credential compromise.
Isolate the PRTG Network Monitor server within a segmented network zone to limit exposure.
Regularly back up configuration and monitoring data to enable rapid recovery in case of service disruption.
Stay informed on Paessler’s official channels for patches or updates addressing this vulnerability and apply them promptly once available.
Consider temporary disabling or limiting the Notification Contacts feature if feasible until a patch is released.

Description

CVE-2025-67835 is a medium-severity vulnerability in Paessler PRTG Network Monitor versions before 25.4.114 that allows an authenticated attacker to cause a Denial-of-Service (DoS) via the Notification Contacts functionality. The vulnerability does not impact confidentiality or integrity but can disrupt availability by exhausting resources. Exploitation requires authentication but no user interaction. There are no known exploits in the wild, and no patches have been linked yet. The vulnerability is classified under CWE-400, indicating resource exhaustion issues. European organizations using PRTG Network Monitor should be aware of this risk, especially those with critical network monitoring dependencies. Mitigation involves restricting access to the Notification Contacts feature, monitoring for unusual activity, and applying updates once available. Countries with high adoption of Paessler products and significant critical infrastructure are most at risk.

Impact

For European organizations, this vulnerability could disrupt critical network monitoring operations, potentially delaying detection of network outages or security incidents. Organizations in sectors such as telecommunications, finance, energy, and government, which rely heavily on continuous network monitoring, may experience operational impacts if the DoS is exploited. Although the vulnerability requires authentication, insider threats or compromised credentials could be leveraged to launch attacks. The unavailability of monitoring services could lead to cascading failures or delayed incident response, increasing the risk of broader security incidents or operational downtime. The medium severity rating reflects the limited scope to availability but highlights the importance of network monitoring in maintaining organizational resilience.

Summary

CVE-2025-67835 is a Denial-of-Service vulnerability affecting Paessler PRTG Network Monitor versions prior to 25.4.114. The flaw resides in the Notification Contacts functionality, which can be exploited by an authenticated attacker to trigger resource exhaustion, leading to service disruption. Specifically, this vulnerability falls under CWE-400, indicating that the system can be overwhelmed by excessive resource consumption. The attack vector is network-based (AV:N), requires low attack complexity (AC:L), and privileges (PR:L) but no user interaction (UI:N). The scope is unchanged (S:U), and the impact affects only availability (A:H), with no confidentiality (C:N) or integrity (I:N) impact. While no public exploits are currently known, the vulnerability poses a risk to organizations relying on PRTG for network monitoring and alerting, as a successful DoS could impair their ability to detect and respond to network issues. The lack of an available patch at the time of reporting necessitates interim mitigation strategies. The vulnerability was reserved in December 2025 and published in January 2026, indicating recent discovery and disclosure.

CWE-400Uncontrolled Resource Consumption (opens in a new tab)
Class weaknessLikelihood of exploit: High
The product does not properly control the allocation and maintenance of a limited resource.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
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. A strong authentication and access control model will help prevent such attacks from occurring in the first place.
Architecture and Design
Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, or; uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed.
Architecture and Design
Ensure that protocols have specific limits of scale placed on them.
OWASP Cheat Sheets
File Upload (opens in a new tab)
OWASP ASVS 4.0.3
V12.1.1 (opens in a new tab)
Attack patterns
XML Ping of the Death (opens in a new tab)
Regular Expression Exponential Blowup (opens in a new tab)
Sustained Client Engagement (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 21 Jan 2026, 20:42 UTC

WeaknessesCWE-400

Technical details

References

Community reviews

Related threats