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.

AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CWE-89

https://cna.erlef.org/cves/CVE-2026-66838.html

https://github.com/elixir-ecto/ecto/security/advisories/GHSA-3gww-3f36-2388

https://github.com/elixir-ecto/postgrex/commit/4011be852c99dc61ddb98cb01aa41e8775a0e3dd

https://github.com/elixir-ecto/postgrex/commit/e1ecba618ddea4cee2556bd6ad9b6285e05f9d3c

https://osv.dev/vulnerability/EEF-CVE-2026-66838

[{"vendor":"elixir-ecto","product":"postgrex","defaultStatus":"unaffected","collectionURL":"https://repo.hex.pm","packageName":"postgrex","cpes":["cpe:2.3:a:elixir-ecto:postgrex:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Postgrex'","'Elixir.Postgrex.Protocol'"],"programFiles":["lib/postgrex.ex","lib/postgrex/protocol.ex"],"programRoutines":[{"name":"'Elixir.Postgrex':stream/4"},{"name":"'Elixir.Postgrex.Protocol':parse_describe_comment_msgs/3"}],"repo":"https://github.com/elixir-ecto/postgrex","packageURL":"pkg:hex/postgrex","versions":[{"version":"0.19.3","lessThan":"0.22.4","versionType":"semver","status":"affected"}]},{"vendor":"elixir-ecto","product":"postgrex","defaultStatus":"unaffected","collectionURL":"https://github.com","packageName":"elixir-ecto/postgrex","cpes":["cpe:2.3:a:elixir-ecto:postgrex:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Postgrex'","'Elixir.Postgrex.Protocol'"],"programFiles":["lib/postgrex.ex","lib/postgrex/protocol.ex"],"programRoutines":[{"name":"'Elixir.Postgrex':stream/4"},{"name":"'Elixir.Postgrex.Protocol':parse_describe_comment_msgs/3"}],"repo":"https://github.com/elixir-ecto/postgrex","packageURL":"pkg:github/elixir-ecto/postgrex","versions":[{"version":"4971a2722fa72f8e1b54a2c403cad4c43916e36d","lessThan":"*","versionType":"git","status":"affected","changes":[{"at":"e1ecba618ddea4cee2556bd6ad9b6285e05f9d3c","status":"unaffected"},{"at":"4011be852c99dc61ddb98cb01aa41e8775a0e3dd","status":"unaffected"}]}]}]