{
  "guidislink": false,
  "id": "https://tailscale.com/security-bulletins/#ts-2026-010",
  "link": "https://tailscale.com/security-bulletins/#ts-2026-010",
  "links": [
    {
      "href": "https://tailscale.com/security-bulletins/#ts-2026-010",
      "rel": "alternate",
      "type": "text/html"
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  "published": "Fri, 24 Jul 2026 00:00:00 GMT",
  "summary": "\u003cp\u003e\u003cstrong\u003e\u003cem\u003eDescription\u003c/em\u003e\u003c/strong\u003e: Tailscale SSH exposed accepted environment variable values on the command line of a local process, disclosing them to other local users and to logs.\u003c/p\u003e\n\u003ch4\u003eWhat happened?\u003c/h4\u003e\n\u003cp\u003e\u003ca href=\"https://tailscale.com/docs/features/tailscale-ssh\"\u003eTailscale SSH\u003c/a\u003e allows the configured \u003ccode\u003eacceptEnv\u003c/code\u003e environment variables to be forwarded from an SSH client to the process launched on the host. Previously, these accepted variables were JSON-encoded and passed to a child process via an \u003ccode\u003e--encoded-env\u003c/code\u003e command line flag.\u003c/p\u003e\n\u003cp\u003eAs a result, the names and values of the forwarded environment variables were visible in \u003ccode\u003e/proc/\u0026#x3c;pid\u003e/cmdline\u003c/code\u003e to any other local user on the host for the duration of process startup. They were also recorded in the session-start arguments that Tailscale logs locally and, unless the node was configured with \u003ccode\u003e--no-logs-no-support\u003c/code\u003e, to \u003ccode\u003elog.tailscale.com\u003c/code\u003e. Environment variables commonly carry secrets such as tokens or credentials, which could therefore be disclosed to unintended parties.\u003c/p\u003e\n\u003cp\u003eTailscale SSH now passes accepted environment variables to the child process through an inherited file descriptor rather than on the command line and keeps their values out of session logs.\u003c/p\u003e\n\u003cp\u003eThis vulnerability is fixed in Tailscale version 1.102.1 or newer.\u003c/p\u003e\n\u003ch4\u003eWhat was the impact?\u003c/h4\u003e\n\u003cp\u003eSecrets carried in forwarded environment variables could be disclosed to other local users on the host via \u003ccode\u003e/proc\u003c/code\u003e, and were written to session logs both locally and to \u003ccode\u003elog.tailscale.com\u003c/code\u003e.\u003c/p\u003e\n\u003ch4\u003eWho was affected?\u003c/h4\u003e\n\u003cp\u003eUsers of Tailscale SSH who forward environment variables via \u003ccode\u003eacceptEnv\u003c/code\u003e, particularly on shared hosts with other local users.\u003c/p\u003e\n\u003ch4\u003eWhat do I need to do?\u003c/h4\u003e\n\u003cp\u003eIf you use Tailscale SSH with \u003ccode\u003eacceptEnv\u003c/code\u003e, upgrade to Tailscale version 1.102.1 or newer. If you use \u003ccode\u003eacceptEnv\u003c/code\u003e to pass credentials, revoke and rotate any impacted credentials.\u003c/p\u003e\n\u003ch4\u003eCredits\u003c/h4\u003e\n\u003cp\u003eWe would like to thank Dante Bertana for reporting this issue.\u003c/p\u003e",
  "summary_detail": {
    "base": "https://tailscale.com/security-bulletins/index.xml",
    "language": null,
    "type": "text/html",
    "value": "\u003cp\u003e\u003cstrong\u003e\u003cem\u003eDescription\u003c/em\u003e\u003c/strong\u003e: Tailscale SSH exposed accepted environment variable values on the command line of a local process, disclosing them to other local users and to logs.\u003c/p\u003e\n\u003ch4\u003eWhat happened?\u003c/h4\u003e\n\u003cp\u003e\u003ca href=\"https://tailscale.com/docs/features/tailscale-ssh\"\u003eTailscale SSH\u003c/a\u003e allows the configured \u003ccode\u003eacceptEnv\u003c/code\u003e environment variables to be forwarded from an SSH client to the process launched on the host. Previously, these accepted variables were JSON-encoded and passed to a child process via an \u003ccode\u003e--encoded-env\u003c/code\u003e command line flag.\u003c/p\u003e\n\u003cp\u003eAs a result, the names and values of the forwarded environment variables were visible in \u003ccode\u003e/proc/\u0026#x3c;pid\u003e/cmdline\u003c/code\u003e to any other local user on the host for the duration of process startup. They were also recorded in the session-start arguments that Tailscale logs locally and, unless the node was configured with \u003ccode\u003e--no-logs-no-support\u003c/code\u003e, to \u003ccode\u003elog.tailscale.com\u003c/code\u003e. Environment variables commonly carry secrets such as tokens or credentials, which could therefore be disclosed to unintended parties.\u003c/p\u003e\n\u003cp\u003eTailscale SSH now passes accepted environment variables to the child process through an inherited file descriptor rather than on the command line and keeps their values out of session logs.\u003c/p\u003e\n\u003cp\u003eThis vulnerability is fixed in Tailscale version 1.102.1 or newer.\u003c/p\u003e\n\u003ch4\u003eWhat was the impact?\u003c/h4\u003e\n\u003cp\u003eSecrets carried in forwarded environment variables could be disclosed to other local users on the host via \u003ccode\u003e/proc\u003c/code\u003e, and were written to session logs both locally and to \u003ccode\u003elog.tailscale.com\u003c/code\u003e.\u003c/p\u003e\n\u003ch4\u003eWho was affected?\u003c/h4\u003e\n\u003cp\u003eUsers of Tailscale SSH who forward environment variables via \u003ccode\u003eacceptEnv\u003c/code\u003e, particularly on shared hosts with other local users.\u003c/p\u003e\n\u003ch4\u003eWhat do I need to do?\u003c/h4\u003e\n\u003cp\u003eIf you use Tailscale SSH with \u003ccode\u003eacceptEnv\u003c/code\u003e, upgrade to Tailscale version 1.102.1 or newer. If you use \u003ccode\u003eacceptEnv\u003c/code\u003e to pass credentials, revoke and rotate any impacted credentials.\u003c/p\u003e\n\u003ch4\u003eCredits\u003c/h4\u003e\n\u003cp\u003eWe would like to thank Dante Bertana for reporting this issue.\u003c/p\u003e"
  },
  "title": "TS-2026-010",
  "title_detail": {
    "base": "https://tailscale.com/security-bulletins/index.xml",
    "language": null,
    "type": "text/plain",
    "value": "TS-2026-010"
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}