VulnerabilityPublished 20 Nov 2025Updated 1 Dec 2025

CVE-2025-55126: Revive Adserver · Cross-site Scripting

Affects Revive AdserverSource CVE Database V5

Not known to be exploited · CVSS 6.5 Medium.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 3.0 base score

6.5Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 13% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: None

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: 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 impacted component.
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 on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 20 Nov 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 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

Affected software

Product	Affected	Fixed in
Revive Revive Adserver	Affected =6	Fixed in–

AI-suggested

To mitigate CVE-2025-55126, European organizations should implement the following specific measures: 1) Immediately audit all instances of Revive Adserver version 6 to identify exposure to the vulnerability. 2) Apply any official patches or updates released by the Revive project as soon as they become available. 3) In the absence of patches, implement strict input validation and output encoding on campaign name fields to prevent injection of malicious scripts. 4) Deploy Content Security Policies (CSP) that restrict the execution of inline scripts and limit sources of executable code to trusted domains. 5) Conduct regular security reviews and penetration testing focused on web application vulnerabilities, including XSS. 6) Educate administrators and users about the risks of XSS and encourage cautious handling of campaign names and other user-generated content. 7) Monitor web server and application logs for suspicious activity indicative of exploitation attempts. 8) Consider isolating the adserver environment or restricting access to trusted IP ranges to reduce exposure. 9) Integrate web application firewalls (WAF) with rules designed to detect and block XSS payloads targeting the adserver. 10) Maintain an incident response plan to quickly address any detected exploitation attempts.

Description

HackerOne community member Dang Hung Vi (vidang04) has reported a stored XSS vulnerability involving the navigation box at the top of advertiser-related pages, with campaign names being the vector for the stored XSS

Impact

For European organizations, the impact of CVE-2025-55126 can be significant, particularly for those heavily reliant on Revive Adserver to manage digital advertising campaigns. Exploitation could lead to unauthorized access to sensitive campaign data, manipulation of ad content, or compromise of user sessions, potentially resulting in reputational damage and loss of trust from advertisers and clients. Confidentiality breaches could expose business-sensitive information, while integrity violations might allow attackers to alter ad campaigns or analytics data, skewing marketing efforts and financial reporting. Although availability is not directly impacted, the indirect effects of a successful attack could disrupt advertising operations. Given the medium severity and ease of exploitation without authentication, attackers could leverage this vulnerability to establish footholds within affected networks or pivot to more critical systems. European organizations must consider compliance with data protection regulations such as GDPR, as exploitation leading to data leakage could result in regulatory penalties. The threat is particularly relevant for digital marketing agencies, media companies, and any enterprises using Revive Adserver as part of their online advertising infrastructure.

Summary

CVE-2025-55126 is a stored cross-site scripting (XSS) vulnerability identified in Revive Adserver version 6, an open-source ad serving platform widely used for managing and delivering online advertisements. The vulnerability arises from insufficient sanitization of campaign names that are displayed within the navigation box on advertiser-related pages. An attacker can craft malicious JavaScript payloads embedded within campaign names, which are then stored by the server and executed in the browsers of users who access these pages. This stored XSS flaw allows attackers to execute arbitrary scripts in the context of the victim's session, potentially leading to theft of authentication tokens, user impersonation, or unauthorized actions within the adserver interface. The vulnerability requires no authentication or user interaction, increasing its risk profile. The CVSS 3.0 base score of 6.5 reflects a medium severity, with network attack vector, low attack complexity, no privileges required, and no user interaction needed. The impact affects confidentiality and integrity but not availability. Although no public exploits are currently known, the vulnerability is publicly disclosed and should be addressed promptly. The lack of an official patch at the time of disclosure necessitates interim mitigations such as input validation and output encoding. This vulnerability is categorized under CWE-79, which covers cross-site scripting issues. Organizations relying on Revive Adserver for their advertising infrastructure should assess their exposure and implement appropriate security controls to mitigate the risk.

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

hackerone.com/reports/3411750 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 4 Dec 2025, 20:59 UTC

WeaknessesCWE-79

Technical details

References

Community reviews

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