CVE-2026-1774 is a critical-severity (CVSS 9.8) vulnerability in @casl/ability. A fix is available for @casl/ability — see the affected versions and patch details below.
CASL Ability is Vulnerable to Prototype Pollution
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-1774.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@casl/abilitynpmDescription
CASL Ability, versions 2.4.0 through 6.7.4, contains a prototype pollution vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @casl/ability | ≥ 2.4.0&&< 6.7.5 | 6.7.5npm install @casl/ability@6.7.5 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @casl/ability, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @casl/ability to 6.7.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-1774 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2026-1774 in your dependencies?
Find it across npm, including transitive dependencies.