CVE-2025-63708VulnerabilityPublished 17 Nov 2025

CVE-2025-63708: n/a

Source CVE Database V5

Not known to be exploited · CVSS 6.1 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

6.1Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 21% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Changed
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: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
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 17 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 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

AI-suggested

To mitigate CVE-2025-63708, organizations should implement strict input validation and sanitization on all font family name inputs within the webfonts API to prevent injection of malicious scripts. Employing a robust Content Security Policy (CSP) that restricts the execution of inline scripts and limits sources for fonts and scripts can significantly reduce exploitation risk. Monitoring and logging fetch requests to the webfonts endpoint for unusual or unexpected payloads can help detect attempted exploitation. Web application firewalls (WAFs) should be configured to identify and block suspicious requests targeting font APIs. Developers should review and update the SourceCodester AI Font Matcher to the latest patched version once available, or apply custom patches to sanitize inputs. Additionally, educating developers about securing less obvious input vectors like font names is critical. Regular security assessments and penetration testing focusing on client-side injection vectors will help identify similar vulnerabilities. Finally, organizations should ensure that user sessions are protected with secure cookie attributes (HttpOnly, Secure, SameSite) to limit the impact of session theft.

Description

Cross-Site Scripting (XSS) vulnerability exists in SourceCodester AI Font Matcher (nid=18425, 2025-10-10) that allows remote attackers to execute arbitrary JavaScript in victims' browsers. The vulnerability occurs in the webfonts API handling mechanism where font family names are not properly sanitized. An attacker can intercept fetch requests to the webfonts endpoint and inject malicious JavaScript payloads through font family names, resulting in session cookie theft, account hijacking, and unauthorized actions performed on behalf of authenticated users. The vulnerability can be exploited by injecting a fetch hook that returns controlled font data containing malicious scripts.

Impact

For European organizations, this vulnerability poses a substantial risk to web applications that utilize the SourceCodester AI Font Matcher or similar font handling APIs. The primary impact is on the confidentiality and integrity of user sessions, as attackers can steal session cookies and hijack accounts. This can lead to unauthorized access to sensitive data, manipulation of user actions, and potential lateral movement within affected systems. Organizations in sectors such as finance, healthcare, and e-commerce, which rely heavily on web applications for customer interaction, are particularly vulnerable. The exploitation could result in data breaches, financial loss, reputational damage, and regulatory penalties under GDPR due to compromised personal data. Additionally, the vulnerability could be leveraged as an initial foothold for more complex attacks, including phishing campaigns or malware distribution. The remote and unauthenticated nature of the exploit increases the attack surface, making it easier for threat actors to target multiple organizations simultaneously. The absence of known exploits in the wild currently limits immediate widespread impact but does not diminish the potential severity once exploitation techniques become publicly available.

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

Description

AI analysisMachine-generated, updated 17 Nov 2025, 16:17 UTC

WeaknessesCWE-79

Technical details

References

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