CVE-2026-45288 — Marten has an injection vulnerability in Marten —...

## Summary Marten's full-text search APIs interpolated the user-supplied `regConfig` parameter directly into the generated SQL without parameterization or validation, making every code path that exposes `regConfig` to untrusted input a SQL injection sink. ## Affected APIs - `IQuerySession.SearchAsync<T>(string searchTerm, string regConfig, ...)` - `IQuerySession.PlainTextSearchAsync<T>(...)` - `IQuerySession.PhraseSearchAsync<T>(...)` - `IQuerySession.WebStyleSearchAsync<T>(...)` - `IQuerySession.PrefixSearchAsync<T>(...)` - `IQueryable<T>.Where(x => x.Search(term, regConfig))` and the matching `PlainTextSearch` / `PhraseSearch` / `WebStyleSearch` / `PrefixSearch` extension methods ## Details In the affected versions, [`FullTextWhereFragment`](https://github.com/JasperFx/marten/blob/master/src/Marten/Linq/SqlGeneration/Filters/FullTextWhereFragment.cs) renders the WHERE-clause SQL by string interpolation: ```csharp private string Sql => $"to_tsvector('{_regConfig}'::regconfig, {_dataConfig}) @@ {_searchFunction}('{_regConfig}'::regconfig, ?)"; ``` `_regConfig` arrives unchanged from the public API surface above. Any value containing a single quote terminates the SQL literal and lets an attacker append arbitrary PostgreSQL. ### Confirmed exploit shapes (with `regConfig` set to attacker-controlled input) | Goal | Payload | | --- | --- | | Time-based blind | `english'::text); SELECT pg_sleep(5); --` | | Information disclosure | `english'; SELECT version(); --` | | DDL execution | `english'; DROP TABLE mt_doc_article; --` | All five overloads listed above produced SQL containing the verbatim payload. ## Impact - **Confidentiality**: an attacker can append arbitrary `SELECT` statements and exfiltrate database contents through error channels, response timing, or — if the application surfaces query results — directly. - **Integrity / Availability**: DDL, `UPDATE`, `DELETE`, and `pg_sleep`-style denial-of-service payloads succeed under the same vector. Concrete impact depends on the database role used by the Marten connection string. - **Precondition**: the calling application must forward attacker-controlled input into the `regConfig` parameter (e.g. a `?lang=` query string mapped to `regConfig`). Applications that hard-code `regConfig` to a compile-time constant are not exploitable. ## Patches Fixed in **Marten 8.36.1** (and forward) by [#4343](https://github.com/JasperFx/marten/pull/4343). `FullTextWhereFragment` now validates `regConfig` against `^[a-zA-Z_][a-zA-Z0-9_]*(\.[a-zA-Z_][a-zA-Z0-9_]*)?$` (a simple PostgreSQL identifier, optionally schema-qualified, capped at `NAMEDATALEN-1` per side) and throws `ArgumentException` for anything else. The default value (`"english"`), schema-qualified configs (`"pg_catalog.english"`), and the standard PostgreSQL text-search configurations all continue to work. ## Workarounds If users cannot upgrade immediately, do **one** of the following at the application boundary: 1. Hard-code `regConfig` to a compile-time constant (`"english"`, `"simple"`, …) and never accept it from request input. 2. Validate any externally-sourced `regConfig` value before passing it to Marten — e.g. against the same regex as the patch (`^[a-zA-Z_][a-zA-Z0-9_]*(\.[a-zA-Z_][a-zA-Z0-9_]*)?$`) or against an allowlist of PostgreSQL configurations the application actually uses. 3. Drop the `regConfig` argument from the call site so Marten falls back to the safe default. ## Resources - Patch PR: [JasperFx/marten#4343](https://github.com/JasperFx/marten/pull/4343) - Patched file: [`FullTextWhereFragment.cs`](https://github.com/JasperFx/marten/blob/master/src/Marten/Linq/SqlGeneration/Filters/FullTextWhereFragment.cs) - Regression tests: [`full_text_regconfig_sql_injection.cs`](https://github.com/JasperFx/marten/blob/master/src/LinqTests/Bugs/full_text_regconfig_sql_injection.cs) - CWE-89: <https://cwe.mitre.org/data/definitions/89.html> ## Credit Reported privately to the JasperFx team with a working proof of concept covering all five affected overloads.