# CVE-2026-127209: Xiaomi Mi Browser < 14.66.0 Path Traversal via ThirdDocViewerActivity

Status: published. Published: 2026-11-12. Updated: 2026-11-13.

Xiaomi Mi Browser Android Application (com.mi.globalbrowser) before 14.66.0-gn contains a path traversal vulnerability in the exported ThirdDocViewerActivity component, where CopyExternalFile.copyFromUri() copies content provider streams using an unsanitized filename from the _display_name column without basename reduction or canonical-path checks. A zero-permission co-resident malicious application can supply a crafted content provider with a _display_name containing .. sequences to make the browser write attacker-controlled bytes to an arbitrary path within its external storage directory, escaping the intended cache_docs staging location without requiring user interaction.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Xiaomi / Mi Browser (com.mi.globalbrowser): ≥ 0; < 14.66.0 (affected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 5.1 (medium); CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 4 (medium); CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N; source: CNA: VulnCheck

- CVSS 4.0: 5.1 (medium); CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/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; source: NVD: disclosure@vulncheck.com

- CVSS 3.1: 4 (medium); CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N; source: NVD: disclosure@vulncheck.com

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: exploitation poc; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-22

## Exploit evidence

- exploit: https://github.com/actuator/cve/blob/main/Xiaomi/2026.07.09%20CVD%20-%20Xiaomi%20Mi%20Browser.md (CNA: VulnCheck)
- exploit: https://github.com/actuator/cve/blob/main/Xiaomi/2026.07.09%20CVD%20-%20Xiaomi%20Mi%20Browser.md (ADP: CISA-ADP)

## References

- https://github.com/actuator/cve/blob/main/Xiaomi/2026.07.09%20CVD%20-%20Xiaomi%20Mi%20Browser.md (CNA: VulnCheck; technical-description, exploit)

- https://www.vulncheck.com/advisories/xiaomi-mi-browser-path-traversal-via-thirddocvieweractivity (CNA: VulnCheck; third-party-advisory)

- https://github.com/actuator/cve/blob/main/Xiaomi/2026.07.09%20CVD%20-%20Xiaomi%20Mi%20Browser.md (ADP: CISA-ADP; exploit)

- https://github.com/actuator/cve/blob/main/Xiaomi/2026.07.09%20CVD%20-%20Xiaomi%20Mi%20Browser.md (disclosure@vulncheck.com)

- https://www.vulncheck.com/advisories/xiaomi-mi-browser-path-traversal-via-thirddocvieweractivity (disclosure@vulncheck.com)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-127209; retrieved 2026-11-13; source updated 2026-11-13

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-127209; retrieved 2026-11-13; source updated 2026-11-12

Revision: e825f181fb8b0d89964cd8071646808a01b38ec54ac639580ce1cb8d266cda75

Canonical: https://y2.dev/cve/CVE-2026-127209

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.