VulnerabilityPublished 27 Feb 2026

CVE-2026-3302: SourceCodester Doctor Appointment System · Cross-site Scripting

Affects SourceCodester Doctor Appointment SystemSource CVE Database V5

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Public exploit available · CVSS 5.3 Medium.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 4.0 base score

5.3Medium

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 34% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/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: None
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: 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: 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 27 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CVSS exploit maturity: proof of concept public
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), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 29 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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
SourceCodesterDoctor Appointment System	Affected =1.0	Fixed in–

AI-suggested

To mitigate CVE-2026-3302, organizations should implement strict input validation on the Email parameter within /register.php, ensuring that only properly formatted email addresses are accepted. Employing server-side validation in addition to client-side checks is critical. Output encoding or escaping should be applied to all user-supplied data before rendering it in HTML contexts to prevent script execution. Utilizing security libraries or frameworks that automatically handle XSS protection can reduce human error. Web application firewalls (WAFs) can provide an additional layer of defense by detecting and blocking malicious payloads targeting this parameter. Organizations should monitor for suspicious activity related to user registration and educate users about the risks of interacting with untrusted links. Finally, contacting the vendor or community maintaining the SourceCodester Doctor Appointment System to request or develop an official patch is recommended to ensure long-term security.

Description

A weakness has been identified in SourceCodester Doctor Appointment System 1.0. Affected by this issue is some unknown functionality of the file /register.php of the component Sign Up Page. Executing a manipulation of the argument Email can lead to cross site scripting. The attack can be launched remotely. The exploit has been made available to the public and could be used for attacks.

Impact

The primary impact of CVE-2026-3302 is on the confidentiality and integrity of user data within the affected Doctor Appointment System. Successful exploitation can allow attackers to execute arbitrary scripts in the context of the victim’s browser, potentially leading to theft of session cookies, personal information, or credentials. This can facilitate further attacks such as account takeover or unauthorized access to sensitive patient data. While the vulnerability does not directly affect system availability, the resulting compromise can damage organizational reputation, violate patient privacy regulations, and lead to compliance penalties. Healthcare organizations relying on this system may face increased risk of targeted phishing or social engineering attacks leveraging the XSS vulnerability. The remote exploitability and lack of required privileges make this a viable vector for attackers seeking to compromise user trust and data integrity in medical appointment environments.

Summary

CVE-2026-3302 identifies a cross-site scripting vulnerability in SourceCodester Doctor Appointment System version 1.0, specifically within the /register.php script handling the Sign Up Page. The vulnerability arises from improper input validation and sanitization of the Email parameter, which allows an attacker to inject arbitrary JavaScript code. When a victim interacts with a maliciously crafted input—such as clicking a link or submitting a form containing the injected script—the attacker’s code executes in the victim’s browser context. This can lead to session hijacking, credential theft, or unauthorized actions performed on behalf of the user. The vulnerability is remotely exploitable without requiring authentication, increasing its risk profile. Although no active exploits have been reported in the wild, the availability of proof-of-concept code lowers the barrier for attackers to develop functional exploits. The vulnerability does not affect the availability of the system but compromises confidentiality and integrity to some extent. The CVSS 4.0 vector indicates network attack vector, low attack complexity, no privileges or user interaction required for the attacker, but user interaction is needed for the victim, and limited impact on integrity. The absence of patches or vendor advisories at this time necessitates immediate mitigation through input validation and output encoding best practices.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 27 Feb 2026, 06:42 UTC

Technical details

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