CVE-2026-6594
CVE-2026-6594 is a high-severity vulnerability with a CVSS 3.x base score of 7.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-94.
Key facts
- Severity: High (CVSS 3.x base score 7.3)
- CVSS v2: 7.5
- CVSS v4: 6.9
- EPSS exploit prediction: 0% (26th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-23742
- Weakness: CWE-94
- Published:
- Last modified:
Description
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.
Frequently asked questions
- What is 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.
- How severe is CVE-2026-6594?
- CVE-2026-6594 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
- Is CVE-2026-6594 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (26th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-6594?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-6594 have an EU (EUVD) identifier?
- Yes. CVE-2026-6594 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-23742.
- When was CVE-2026-6594 published?
- CVE-2026-6594 was published on 2026-04-20 and last updated on 2026-06-17.
References
- https://github.com/sudo-secure/security-research/blob/main/brikcss-merge/prototype-pollution/PoC.md
- https://vuldb.com/submit/791805
- https://vuldb.com/vuln/358229
- https://vuldb.com/vuln/358229/cti
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