CVE-2025-66939: 66biolinks · Cross-site Scripting
Affects 66biolinksSource CVE Database V5
Not known to be exploited · CVSS 5.4 Medium.
Data as of 26 Oct 2026, 14:05 UTC
- 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:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 12 Jan 2026
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.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Packagistaltumcode/66biolinkspkg:composer/altumcode/66biolinksOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Organizations should immediately review their use of 66biolinks version 61.0.1 and restrict or monitor favicon file uploads or references. Implement strict input validation and sanitization for all file uploads, including favicons, ensuring that only valid image formats without embedded scripts are accepted. Employ Content Security Policy (CSP) headers to limit the execution of unauthorized scripts in browsers. Monitor web application logs for unusual favicon upload activity or errors related to favicon processing. Engage with AltumCode to obtain patches or updates addressing this vulnerability and apply them promptly once available. Additionally, conduct security awareness training for developers and administrators on the risks of XSS via non-traditional vectors like favicon files. Consider deploying web application firewalls (WAFs) with rules targeting malicious favicon payloads as an interim protective measure. Finally, perform regular security testing and code reviews focusing on input handling and file processing components.
Description
Cross Site Scripting vulnerability in 66biolinks by AltumCode v.61.0.1 allows an attacker to execute arbitrary code via a crafted favicon file