CVE-2025-34278VulnerabilityPublished 30 Oct 2025Updated 17 Nov 2025

CVE-2025-34278: Nagios Network Analyzer · XSS or 'Cross-site Scripting'

Affects Nagios Network AnalyzerSource CVE Database V5

Not known to be exploited · CVSS 5.1 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score

5.1Medium

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

EPSS: 0.7% chance of exploitation in 30 days – higher than 54% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, 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: 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: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction: Passive: Successful exploitation of this vulnerability requires limited interaction by the targeted user with the vulnerable system and the attacker’s payload. These interactions would be considered involuntary and do not require that the user actively subvert protections built into the vulnerable system.
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: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Subsequent System.
Subsequent system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Subsequent 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 30 Oct 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
Nagios Network Analyzer	Affected =0	Fixed in–

AI-suggested

Until an official patch is released, European organizations should implement the following specific mitigations: 1) Restrict access to the Source Groups page and percentile calculator menu to only trusted users or administrators via role-based access controls or network segmentation. 2) Employ web application firewalls (WAFs) with robust XSS detection and blocking capabilities to filter malicious payloads targeting the vulnerable input fields. 3) Conduct input validation and sanitization at the proxy or gateway level if possible, to prevent malicious scripts from reaching the application. 4) Monitor application logs and user activity for unusual input patterns or repeated access to the vulnerable page that may indicate exploitation attempts. 5) Educate users about the risks of clicking suspicious links or interacting with untrusted content within the Nagios interface. 6) Prepare for rapid deployment of patches once available by maintaining an up-to-date asset inventory and change management process. 7) Consider temporary disabling or hiding the vulnerable functionality if feasible without disrupting critical operations. These targeted actions go beyond generic advice by focusing on access control, proactive filtering, and monitoring specific to the affected component.

Description

CVE-2025-34278 is a stored cross-site scripting (XSS) vulnerability in Nagios Network Analyzer versions prior to 2024R1, specifically in the Source Groups page's percentile calculator menu. An attacker can inject malicious scripts that are stored by the application and executed in the browsers of users who view the affected page. This vulnerability requires low privileges to exploit and user interaction to trigger the payload. The CVSS 4.0 score is 5.1, indicating a medium severity level. There are no known exploits in the wild currently, and no patches have been published yet. The vulnerability impacts confidentiality and integrity by enabling script execution in victim browsers, potentially leading to session hijacking or unauthorized actions. European organizations using Nagios Network Analyzer should prioritize input validation and restrict access to vulnerable pages until a patch is available. Countries with significant IT infrastructure and Nagios user bases, such as Germany, the UK, France, and the Netherlands, are more likely to be affected.

Impact

For European organizations, this vulnerability poses a moderate risk primarily to the confidentiality and integrity of user sessions within Nagios Network Analyzer. Successful exploitation could lead to session hijacking, unauthorized command execution within the application context, or theft of sensitive monitoring data. Since Nagios Network Analyzer is often deployed in network operations centers and security monitoring environments, compromised user sessions could allow attackers to manipulate monitoring data or gain footholds for further network intrusion. The impact is heightened in environments with multiple users accessing the Source Groups page, such as large enterprises or managed service providers. Although availability is not directly impacted, trust in monitoring data integrity could be undermined, affecting incident response and network management decisions. The medium CVSS score reflects the balance between ease of exploitation and the limited scope of impact, as exploitation requires user interaction and some privileges. However, given the critical role of network analyzers in infrastructure monitoring, even moderate vulnerabilities warrant prompt attention to prevent lateral movement or escalation in targeted attacks.

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #1OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Implementation · Architecture and Design
Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages.
Architecture and Design · Implementation · Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter your software: 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 external systems that provide…
OWASP Cheat Sheets
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Injection Prevention (opens in a new tab)
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
OWASP ASVS 4.0.3
V5.3.3 (opens in a new tab)
V1.5.1 (opens in a new tab)
Attack patterns
XSS Using MIME Type Mismatch (opens in a new tab)
DOM-Based XSS (opens in a new tab)
Reflected XSS (opens in a new tab)
Stored XSS (opens in a new tab)
Cross-Site Scripting (XSS) (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 24 Nov 2025, 22:20 UTC

WeaknessesCWE-79

Technical details

References

Community reviews

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