Vitess vttablet /twopcz reflected XSS

{
  "id": "36030e3cd802c9c8681ff5d4afc8aa0d283221fd9ceaffb4b702ebcbc1edb521",
  "url": "https://osv.dev/vulnerability/GHSA-v75v-6fpf-gvw8",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Vitess vttablet /twopcz reflected XSS",
    "summary": "From: xylove21 To: security@vitess.io Subject: [Security Report] Vitess vttablet /twopcz reflected XSS Date: Tue, 24 Jun 2026 14:30:00 +0800 ## Summary The `twopczHandler` in `go/vt/vttablet/tabletserver/twopcz.go` (line 185) reflects the `Action` and `dtid` form values directly into the HTML response body via `fmt.Fprintln(w, msg)` — **without HTML escaping**. The response is served as `text/html; charset=utf-8`, and Vitess's default `acl` policy is **allow-all**, so the endpoint is reachable by anyone who can hit the vttablet's HTTP port (default `15999`, multiplexed with gRPC and MySQL wire-protocol ports). A crafted `Action` or `dtid` value yields a **reflected XSS** that executes in the operator's browser with same-origin access to the vttablet's debug endpoints. This includes `/queryz` (live query plans), `/querylogz` (recent queries with bound values), `/txlogz` (transactions), `/debug/env` (environment variables — may include MySQL/topology credentials), `/debug/vars` (expvar stats), and `/debug/pprof/*` if enabled. The bug was introduced before v20.0.0 (long-standing) and was silently fixed in commit `3140c1846c` (merged 2026-06-09, PR #20255, \"tabletserver: escape reflected form values in twopcz handler\"). The fix replaces `fmt.Fprintln(w, msg)` with `fmt.Fprintln(w, html.EscapeString(msg))`. **No released version of Vitess contains the fix** — the fix lives only on `main` (current tip `33a3c0fafe69`, 2026-06-23). There is **no CVE, GHSA, or OSV entry** for this spe",
    "evidence": "osv:GHSA-v75v-6fpf-gvw8",
    "products": [
      {
        "name": {
          "value": "vitess.io/vitess",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "0.23.5",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "vitess.io/vitess",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "0.24.2",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "critical",
    "structured": {
      "id": "GHSA-v75v-6fpf-gvw8",
      "aliases": [
        "CVE-2026-104252",
        "GHSA-v75v-6fpf-gvw8"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "0.23.5"
                }
              ]
            }
          ],
          "package": {
            "name": "vitess.io/vitess",
            "purl": "pkg:golang/vitess.io/vitess",
            "ecosystem": "Go"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-v75v-6fpf-gvw8/GHSA-v75v-6fpf-gvw8.json"
          }
        },
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0.24.0"
                },
                {
                  "fixed": "0.24.2"
                }
              ]
            }
          ],
          "package": {
            "name": "vitess.io/vitess",
            "purl": "pkg:golang/vitess.io/vitess",
            "ecosystem": "Go"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-v75v-6fpf-gvw8/GHSA-v75v-6fpf-gvw8.json"
          }
        }
      ],
      "modified": "2026-10-15T20:30:05.447638204Z",
      "provider": "osv",
      "references": [
        "https://github.com/vitessio/vitess/security/advisories/GHSA-v75v-6fpf-gvw8",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-104252",
        "https://github.com/vitessio/vitess/pull/20255",
        "https://github.com/vitessio/vitess/pull/20273",
        "https://github.com/vitessio/vitess/pull/20274",
        "https://github.com/vitessio/vitess/commit/3140c1846cd120db34f33b2083139b4ab638aed2",
        "https://github.com/vitessio/vitess/commit/976e1e0d78f9d29d02e5e31b4aa7e180648f08af",
        "https://github.com/vitessio/vitess/commit/c1ed96302e658190168c971afdac730cf70e43f7",
        "https://github.com/vitessio/vitess",
        "https://github.com/vitessio/vitess/releases/tag/v23.0.5",
        "https://github.com/vitessio/vitess/releases/tag/v24.0.2"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-116",
          "CWE-79",
          "CWE-80"
        ],
        "severity": "CRITICAL",
        "github_reviewed": true,
        "nvd_published_at": "2026-10-13T20:17:12Z",
        "github_reviewed_at": "2026-10-15T20:16:29Z"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-104252",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/database_specific/severity"
  },
  "source_id": "core-osv",
  "document_id": 336044,
  "published_at": "2026-10-15T20:16:29+00:00"
}