RCE in Brikcss Merge
CVE-2026-6594
A vulnerability was determined in brikcss merge up to 1.3.0. This affects an unknown part. Executing a manipulation of the argument __proto__/constructor.prototype/prototype can lead to improperly controlled modification of object prototype attributes. The attack may be performed from remote. The vendor was contacted early about this disclosure but did not respond in any way.
Vulnerability class: RCE (Remote Code Execution)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.006 (44.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 44th percentile — 44.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.006 · change: +0.002
Affected products
- Brikcss Merge — versions 1.0, 1.1, 1.2
Weakness classification (CWE)
References
- vuldb.com/vuln/358229 (technical-description, vdb-entry)
- vuldb.com/vuln/358229/cti (signature, permissions-required)
- vuldb.com/submit/791805 (third-party-advisory)
- github.com/sudo-secure/security-research/blob/main/brikcss-merge/prototype-poll… (exploit)
Frequently asked questions
- What is CVE-2026-6594?
- CVE-2026-6594 is a high-severity vulnerability in Brikcss Merge, classified under Code Injection. CVSS score: 7.3/10. Published 2026-04-20.
- How severe is CVE-2026-6594?
- High severity. CVSS v3 base score is 7.3 out of 10.