CVE-2025-9095VulnerabilityPublished 17 Aug 2025

CVE-2025-9095: ExpressGateway express-gateway · Cross Site Scripting

Affects ExpressGateway express-gatewaySource CVE Database V5

Not known to be exploited · CVSS 5.1 Medium.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 4.0 base score

5.1Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 18% 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:L/VA:N/SC:N/SI:N/SA:N/E:P

Base metrics

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

Threat metrics

Exploit Maturity: POC

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: 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 Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
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.
Exploit Maturity: POC: Based on threat intelligence sources each of the following must apply: · Proof-of-concept is publicly available · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 17 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 2026-10-26.

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
ExpressGateway express-gateway	Affected =1.16.0 =1.16.1 =1.16.2 =1.16.3 =1.16.4 =1.16.5 =1.16.6 =1.16.7 =1.16.8 =1.16.9 =1.16.10	Fixed in–

AI-suggested

Given the absence of official patches, European organizations should implement the following specific mitigations: 1) Conduct an immediate inventory to identify all instances of ExpressGateway express-gateway in use, focusing on versions 1.16.0 through 1.16.10. 2) Apply strict input validation and output encoding on all user-supplied data processed by the REST endpoints, particularly those related to user management routes. 3) Deploy Web Application Firewalls (WAFs) with custom rules designed to detect and block common XSS attack patterns targeting the vulnerable endpoints. 4) Implement Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers interacting with the gateway. 5) Educate users and administrators about the risk of phishing or social engineering attacks that could trigger XSS exploitation. 6) Monitor logs and network traffic for unusual activities or attempted exploitation patterns. 7) Plan for an upgrade or replacement strategy to move to a patched or alternative gateway solution once available. 8) Isolate the express-gateway deployment within network segments with limited exposure to untrusted networks to reduce attack surface. These measures go beyond generic advice by focusing on compensating controls tailored to the specific vulnerability context and product usage.

Description

A flaw has been found in ExpressGateway express-gateway up to 1.16.10. This issue affects some unknown processing in the library lib/rest/routes/users.js of the component REST Endpoint. The manipulation leads to cross site scripting. The attack may be initiated remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Impact

For European organizations using ExpressGateway express-gateway versions 1.16.0 to 1.16.10, this vulnerability poses a risk of client-side attacks that can compromise user sessions, steal sensitive information, or perform unauthorized actions on behalf of users. Since ExpressGateway is often used as an API gateway or microservices management tool, exploitation could lead to broader security issues if attackers leverage stolen credentials or session tokens to access backend services. The impact is particularly significant for organizations handling sensitive personal data or critical business operations, as XSS attacks can facilitate data breaches or unauthorized data manipulation. Additionally, regulatory frameworks such as GDPR impose strict requirements on data protection; a successful attack exploiting this vulnerability could lead to compliance violations and associated penalties. The lack of vendor response and patches means European organizations must proactively assess their exposure and implement mitigations to reduce risk. The medium severity rating suggests the threat is moderate but should not be underestimated, especially in environments with high-value targets or sensitive user bases.

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 25 Aug 2025, 01:12 UTC

Technical details

References

Community reviews

Related threats