Mafintosh's protocol-buffers-schema is vulnerable to prototype pollution
Priority MEDIUM 62CWE-1321Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · None · Low
- Fix status
- Partial Red Hat: 4 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA, GitHub and Red Hat.
Summary
JavaScript is vulnerable to prototype pollution in Mafintosh's protocol-buffers-schema Version 3.6.0, where an attacker may alter the application logic, bypass security checks, cause a DoS or achieve remote code execution.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00534 45th percentileScored 2026-11-07
Fix Partial Protocol-buffers-schema parser (Mafintosh): 3.6.1protocol-buffers-schema (npm): 3.6.1Red Hat: 4 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| mafintosh | Protocol-buffers-schema parser | 3.6.0 to before 3.6.1 | 3.6.1 | Patch available | CNA |
| — | protocol-buffers-schema (npm) | before 3.6.1 | 3.6.1 | Patch available | GHSA-j452-xhg8-qg39 |
- Protocol-buffers-schema parser Vendormafintosh Affected 3.6.0 to before 3.6.1 Fixed in 3.6.1 Patch available CNA
- protocol-buffers-schema (npm) Vendor— Affected before 3.6.1 Fixed in 3.6.1 Patch available GHSA-j452-xhg8-qg39
Remediation
- Fix · CNA Protocol-buffers-schema parser (Mafintosh) Fixed in 3.6.1
- Fix · GHSA-j452-xhg8-qg39 protocol-buffers-schema (npm) Fixed in 3.6.1 Advisory →
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Cryostat 4 | Affected | No fix yet: Fix deferred |
| Red Hat Developer Hub 1 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift AI (RHOAI) | Affected | No fix yet: Fix deferred |
| Self-service automation portal 2 | Affected | No fix yet: Fix deferred |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-5758
- 2026-10-03 Alias added: GHSA-j452-xhg8-qg39
- 2026-10-25 EPSS moved to the below the 50th percentile
- 2026-10-27 Affected versions changed · Red Hat
References
Other 4
- https://github.com/mafintosh/protocol-buffers-schema/pull/70
- https://morielharush.github.io/2026/04/12/cve-2026-5758-protocol-buffers-schema-prototype-pollution/
- https://github.com/mafintosh/protocol-buffers-schema
- https://morielharush.github.io/2026/04/12/cve-2026-5758-protocol-buffers-schema-prototype-pollution
More mafintosh vulnerabilities
- TI-2025-30712 tar-fs has issue where extract can write outside the specified dir with a specific tarball CVSS 4.0HIGH 8.7
- TI-2025-36904 tar-fs has a symlink validation bypass if destination directory is predictable with a specific tarball CVSS 4.0HIGH 8.7
Sources
- CVE-2026-5758 · CVE Program
- CVE-2026-5758 · NVD
- FIRST EPSS
- GHSA-j452-xhg8-qg39 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-5758 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences