CVE-2026-66838
SQL injection via the :comment option in Postgrex.stream/4
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.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
5.9
SQL injection via the :comment option in Postgrex.stream/4
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.
- Record
CVE-2026-66838- CVSS 4.0
- 5.9 Medium
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 - Weakness
- CWE-89
- Updated
- 2026-11-02
EUVDEUVD-2026-54476
5.9
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.
- Record
EUVD-2026-54476- CVSS 4.0
- 5.9 Medium
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 - Updated
- 2026-11-02
NVD
5.9
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.
- Record
CVE-2026-66838- CVSS 4.0
- 5.9 Medium
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/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 - CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N - Weakness
- CWE-89
- Updated
- 2026-11-02
OSV
5.9
SQL injection via the :comment option in Postgrex.stream/4
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.
- Record
CVE-2026-66838- CVSS 4.0
- 5.9 Medium
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 - Weakness
- CWE-89
- Updated
- 2026-11-02
OSVEEF-CVE-2026-66838
5.9
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.
Workarounds
Reject any :comment value containing */ or a null byte before passing it to Postgrex.stream/4 or Ecto.Repo.stream/2. Alternatively, build comments only from trusted values.
Configurations
The application must pass a :comment derived from untrusted input to Postgrex.stream/4 or Ecto.Repo.stream/2. Applications that omit the option or pass only static values are unaffected.
- Record
EEF-CVE-2026-66838- CVSS 4.0
- 5.9 Medium
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 - Weakness
- CWE-89
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
postgrexHex |
0.19.3 up to 0.22.4, plus listed versions 0.20.00.21.00.21.10.22.00.22.10.22.20.22.3 |
0.22.4 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-66838 is a medium vulnerability (CVSS 5.9) in Elixir-ecto Postgrex, published August 7, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.40%, the 34th percentile. Fixed in postgrex 0.22.4.
References
github.com/elixir-ecto/ecto/security/advisories/GHSA-3gww-3f36-2388
cna.erlef.org/cves/CVE-2026-66838.html
osv.dev/vulnerability/EEF-CVE-2026-66838
github.com/elixir-ecto/postgrex/commit/e1ecba618ddea4cee2556bd6ad9b6285e05f9d3c
github.com/elixir-ecto/postgrex/commit/4011be852c99dc61ddb98cb01aa41e8775a0e3dd
github.com