Prototype Pollution in Stalniy @Casl/ability
CVE-2026-111172
@casl/ability 6.7.5 before 7.0.2 contains a prototype pollution vulnerability in rulesToFields() that allows attackers to modify inherited builtins via dotted condition keys. Attackers controlling rule conditions can supply keys like 'toString.call' to alter shared builtin functions process-wide, causing denial of service for the Node.js process.
Vulnerability class: Prototype Pollution
Published .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/stalniy/casl/commit/58242cb3c7911c8a89bacfb7d732701d81bc1324 (patch)
- github.com/stalniy/casl/pull/1305 (issue-tracking, patch)
- github.com/stalniy/casl/blob/80f2380d03cfe9b162685d510ba8bc0ce83d0598/packages/… (technical-description)
- github.com/stalniy/casl (product)
- www.vulncheck.com/advisories/casl-ability-6.7.5-before-7.0.2-prototype-pollutio… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-111172?
- CVE-2026-111172 is a medium-severity vulnerability in Stalniy @Casl/ability, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 5.3/10. Published 2026-10-15.
- How severe is CVE-2026-111172?
- Medium severity. CVSS v3 base score is 5.3 out of 10.