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Medium

SQL injection via the :comment option in Postgrex.stream/4

Type: advisorySources: OSV

Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') vulnerability in elixir-ecto postgrex allows SQL Injection via the :comment option of Postgrex.stream/4. An attacker who can influence that value can close the comment delimiter with */ and extend the streamed statement with their own clauses, which execute under the connection's role. Ecto exposes the same option through Ecto.Repo.stream/2. Postgrex appends the comment by concatenating it into the statement text sent in the Parse message, without escaping or rejecting */. The option is validated by comment_not_present!/1 at every other execution point; stream/4 never calls it. Because Parse accepts a single command, the injection is confined to the streamed statement and further statements cannot be chained. This issue affects postgrex: from 0.19.3 before 0.22.4.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2026-66838
Confirmed fixed CVEs
Not specified
Updated in this feed
3 Nov 2026, 14:23 UTC · Revision 1

Source evidence

SQL injection via the :comment option in Postgrex.stream/4

core-osv · Original source

Published 7 Aug 2026, 12:20 UTC

Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') vulnerability in elixir-ecto postgrex allows SQL Injection via the :comment option of Postgrex.stream/4. An attacker who can influence that value can close the comment delimiter with */ and extend the streamed statement with their own clauses, which execute under the connection's role. Ecto exposes the same option through Ecto.Repo.stream/2. Postgrex appends the comment by concatenating it into the statement text sent in the Parse message, without escaping or rejecting */. The option is validated by comment_not_present!/1 at every other execution point; stream/4 never calls it. Because Parse accepts a single command, the injection is confined to the streamed statement and further statements cannot be chained. This issue affects postgrex: from 0.19.3 before 0.22.4.

osv:CVE-2026-66838
Complete source record
{
  "id": "c2838d64167bfcfb9e6ae30ed37d4c2855636a32de3551c64163a833e3011789",
  "url": "https://osv.dev/vulnerability/CVE-2026-66838",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "SQL injection via the :comment option in Postgrex.stream/4",
    "summary": "Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') vulnerability in elixir-ecto postgrex allows SQL Injection via the :comment option of Postgrex.stream/4. An attacker who can influence that value can close the comment delimiter with */ and extend the streamed statement with their own clauses, which execute under the connection's role. Ecto exposes the same option through Ecto.Repo.stream/2. Postgrex appends the comment by concatenating it into the statement text sent in the Parse message, without escaping or rejecting */. The option is validated by comment_not_present!/1 at every other execution point; stream/4 never calls it. Because Parse accepts a single command, the injection is confined to the streamed statement and further statements cannot be chained. This issue affects postgrex: from 0.19.3 before 0.22.4.",
    "evidence": "osv:CVE-2026-66838",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-66838",
      "aliases": [
        "CVE-2026-66838",
        "EEF-CVE-2026-66838",
        "GHSA-3gww-3f36-2388"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/elixir-ecto/ecto",
              "type": "GIT",
              "events": [
                {
                  "introduced": "4971a2722fa72f8e1b54a2c403cad4c43916e36d"
                },
                {
                  "fixed": "e1ecba618ddea4cee2556bd6ad9b6285e05f9d3c"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "4971a2722fa72f8e1b54a2c403cad4c43916e36d"
                      },
                      {
                        "fixed": "e1ecba618ddea4cee2556bd6ad9b6285e05f9d3c"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "ChangesAt"
                  }
                ]
              }
            },
            {
              "repo": "https://github.com/elixir-ecto/postgrex",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "4011be852c99dc61ddb98cb01aa41e8775a0e3dd"
                },
                {
                  "fixed": "e1ecba618ddea4cee2556bd6ad9b6285e05f9d3c"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "fixed": "4011be852c99dc61ddb98cb01aa41e8775a0e3dd"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "e1ecba618ddea4cee2556bd6ad9b6285e05f9d3c"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v0.22.2",
            "v0.22.1",
            "v0.21.1",
            "v0.21.0",
            "v0.20.0",
            "v0.19.3",
            "v0.19.2",
            "v0.19.1",
            "v0.19.0",
            "v0.18.0",
            "v0.17.5",
            "v0.17.4",
            "v0.17.3",
            "v0.17.2",
            "v0.17.1",
            "v0.17.0",
            "v0.16.5",
            "v0.16.4",
            "v0.16.3",
            "v0.16.2",
            "v0.16.1",
            "v0.16.0",
            "v0.15.9",
            "v0.15.8",
            "v0.15.7",
            "v0.15.6",
            "v0.15.5",
            "v0.15.4",
            "v0.15.3",
            "v0.15.2",
            "v0.15.1",
            "v0.15.0",
            "v0.14.2",
            "v0.14.1",
            "v0.14.0",
            "v0.14.0-rc.0",
            "v0.12.1",
            "v0.13.2",
            "v0.13.1",
            "v0.13.0",
            "0.13.0-rc.0",
            "v1.0.0-rc.1",
            "v1.0.0-rc.0",
            "v0.12.0",
            "v0.11.2",
            "v0.11.1",
            "v0.11.0",
            "prep_ex",
            "v0.10.0",
            "v0.9.1",
            "v0.9.0",
            "v0.8.4",
            "v0.8.3",
            "v0.8.2",
            "v0.8.1",
            "v0.7.0",
            "v0.6.0",
            "v0.5.5",
            "v0.5.4",
            "v0.5.3",
            "v0.5.2",
            "v0.5.1",
            "v0.5.0",
            "v0.4.2",
            "v0.4.1",
            "v0.4.0",
            "v0.3.1",
            "v0.3.0",
            "v0.2.1",
            "v0.2.0",
            "v0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-66838.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:29.354727023Z",
      "provider": "osv",
      "references": [
        "https://cna.erlef.org/cves/CVE-2026-66838.html",
        "https://github.com",
        "https://osv.dev/vulnerability/EEF-CVE-2026-66838",
        "https://repo.hex.pm",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66838.json",
        "https://github.com/elixir-ecto/ecto/security/advisories/GHSA-3gww-3f36-2388",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-66838",
        "https://github.com/elixir-ecto/postgrex/commit/4011be852c99dc61ddb98cb01aa41e8775a0e3dd",
        "https://github.com/elixir-ecto/postgrex/commit/e1ecba618ddea4cee2556bd6ad9b6285e05f9d3c",
        "https://github.com/elixir-ecto/postgrex"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-89"
        ],
        "cna_assigner": "EEF",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "0.19.3"
                  },
                  {
                    "fixed": "0.22.4"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandardRange"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66838.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-66838",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 496339,
  "published_at": "2026-08-07T12:20:02.376+00:00"
}