CVE-2026-6594 json
brikcss merge prototype pollution
published 2026-04-20 6 mo ago modified 2026-10-26 13 d ago also GHSA-3jc6-6r48-v6qf , EUVD-2026-23742
- cvss
- 7.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 27%
- public exploits
- 0
- none known
Summary
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.
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 6 mo ago
Exploit prediction
0.34% chance of exploitation in the next 30 days, higher than 27% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/sudo-secure/security-research/blob/main/brikcss-merge/prototype-pollution/PoC.md referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 6.9 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X |
| CNA | 3.1 | 7.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:X/RL:X/RC:R |
| CNA | 3.0 | 7.3 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:X/RL:X/RC:R |
| CNA | 2.0 | 7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P/E:ND/RL:ND/RC:UR |
| CNA | 4.0 | 6.9 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| CNA | 3.1 | 7.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L |
| CNA | 2.0 | 7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P |
| GitHub | 3.1 | 7.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | @brikcss/merge | <=1.3.1 |
no fix listed |
Affected products
- brikcss merge
Classification
References
-
github.com
/sudo-secure/security-research/blob/main/brikcss-merge/prototype-pollution/PoC.md
exploit, web
-
vuldb.com
/vuln/358229
vdb-entry, technical-description, web
-
vuldb.com
/vuln/358229/cti
signature, permissions-required, web
-
vuldb.com
/submit/791805
third-party-advisory, web
-
nvd.nist.gov
/vuln/detail/CVE-2026-6594
advisory
-
github.com
/brikcss/merge
package
Sources
- CVE List CVE-2026-6594
- GitHub Advisory GHSA-3jc6-6r48-v6qf
- NVD CVE-2026-6594
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.