CVE-2026-1774
📋 TL;DR
CASL Ability versions 2.4.0 through 6.7.4 contain a prototype pollution vulnerability that allows attackers to modify JavaScript object prototypes, potentially leading to remote code execution or privilege escalation. This affects any application using these vulnerable versions of the CASL Ability authorization library. The vulnerability is particularly dangerous because it can be exploited through user-controlled input.
💻 Affected Systems
- CASL Ability
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data exfiltration, or lateral movement within the network.
Likely Case
Privilege escalation allowing unauthorized access to protected resources or denial of service through application crashes.
If Mitigated
Limited impact to application functionality with proper input validation and security controls in place.
🎯 Exploit Status
Prototype pollution vulnerabilities typically require specific input patterns but can be exploited without authentication if user input reaches vulnerable code paths.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 6.7.5 and later
Vendor Advisory: https://github.com/stalniy/casl/tree/master/packages/casl-ability
Restart Required: Yes
Instructions:
1. Update package.json to specify 'casl-ability': '^6.7.5' or later. 2. Run 'npm update casl-ability' or 'yarn upgrade casl-ability'. 3. Restart all Node.js applications using the library. 4. Test authorization functionality after update.
🔧 Temporary Workarounds
Input Validation and Sanitization
allImplement strict input validation to prevent prototype pollution patterns from reaching CASL Ability functions.
Object.freeze on Prototypes
allFreeze Object.prototype and other critical prototypes to prevent pollution.
Object.freeze(Object.prototype);
Object.freeze(Object);
🧯 If You Can't Patch
- Implement Web Application Firewall (WAF) rules to block prototype pollution patterns in HTTP requests.
- Isolate affected applications in network segments with strict access controls and monitor for suspicious activity.
🔍 How to Verify
Check if Vulnerable:
Check package.json or package-lock.json for casl-ability version. If version is between 2.4.0 and 6.7.4 inclusive, the system is vulnerable.Check Version:
npm list casl-ability | grep casl-abilityVerify Fix Applied:
Verify casl-ability version is 6.7.5 or later using 'npm list casl-ability' or check package.json. Test authorization functionality remains working.📡 Detection & Monitoring
Log Indicators:
- Unusual authorization failures
- Unexpected permission grants
- Application crashes with prototype-related errors
Network Indicators:
- HTTP requests containing unusual object patterns like __proto__ or constructor properties
SIEM Query:
source=web_logs AND ("__proto__" OR "constructor" OR "prototype") AND status=200