---
title: "DSLLogicVerifier NL->DSL bridge returns VERIFIED for contradictory or altered constraints (incomplete fix of GHSA-mfh5-3c8f-975p)"
description: "GHSA-g25v-44j8-gg7x: DSLLogicVerifier NL->DSL bridge returns VERIFIED for contradictory or altered constraints (incomplete fix of GHSA-mfh5-3c8f-975p). Affected and fixed versions of qwed."
url: https://qwedai.com/security/advisories/ghsa-g25v-44j8-gg7x
---

GHSA-g25v-44j8-gg7x

# DSLLogicVerifier NL->DSL bridge returns VERIFIED for contradictory or altered constraints (incomplete fix of GHSA-mfh5-3c8f-975p)

medium Published 16 October 2026

### Impact

On `POST /verify/logic`, the natural-language-to-DSL bridge `_constant_to_dsl` strips quotes from string constants and rewrites them into bare tokens, which the DSL compiler then auto-creates as integer variables. As a result the logic engine returns `status=VERIFIED`, `is_authoritative=True` with a `proof_ref`, for claims that do not hold:

-   Contradictory categorical rules (for example `tier == 'gold'` and `tier == 'silver'`) come back SAT/VERIFIED, because the two distinct strings both become the same auto-created integer variable.
-   Distinct string constants that normalise to the same token, or numeric-looking strings coerced to integers, collapse the same way.

The published fix for GHSA-mfh5-3c8f-975p rejects string literals at the direct-DSL sink, but the NL bridge reaches the compiler through a path that fix never covered, so the same class of false VERIFIED is reachable again.

Note: `admission_decision` returns BLOCKED for these (logic VERIFIED results carry no `is_valid=True`), so a consumer gating strictly on the admission decision is not affected. The exposed surface is the authoritative VERIFIED verdict, its `proof_ref`, and the audit record (`is_verified=true`).

### Affected

All releases through 7.2.3; reproduced at the verdict level on `main` @ a4d6714 (deterministic, post-translation — the LLM step is not involved in the repro).

### Details

-   `src/qwed_new/core/dsl_logic_verifier.py` `_constant_to_dsl` (around 402-404): `re.sub(r"\W+", "_", value)` emits a bare token.
-   `src/qwed_new/core/dsl/compiler.py` (around 161-168): the quote-guard only fires on tokens that still carry quotes; everything else auto-creates an `Int`.
-   A routing test currently asserts the mangling as expected behaviour (`tests/test_dsl_logic_verifier_routing.py`), and `evals/cases/logic.json` has no string-constant cases.

### Fix

Reject string constants in `_constant_to_dsl` (fail closed to UNVERIFIABLE) rather than coercing them to integer variables, so the GHSA-mfh5 quote-guard covers the NL bridge too; update the routing test that locks in the mangling; and add string-constant cases to the logic eval. Tracked as an incomplete fix of GHSA-mfh5-3c8f-975p.

### Source

OpenVuln external audit (2026-10), NL->DSL logic bridge findings. Reported privately.

Affected and fixed

Package

qwed

Affected

<= 7.2.3

Fixed in

7.3.0

Severity

medium

Weakness

CWE-345 Insufficient Verification of Data Authenticity

CWE-697 Incorrect Comparison

[View on GitHub](https://github.com/QWED-AI/qwed-verification/security/advisories/GHSA-g25v-44j8-gg7x)

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