dbcve.org
Path TraversalWeakness · CWE-22

CVE-2026-44635

HIGH · 7.5 CVSS v3.1 Published 2026-05-27
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Kysely is a type-safe TypeScript SQL query builder. From 0.26.0 to 0.28.16, DefaultQueryCompiler.visitJSONPathLeg does not escape JSON-path metacharacters (., [, ], *, **, ?). When attacker-controlled input flows into eb.ref(col, '->$').key(input) or .at(input) — including type-safe code where the JSON column is shaped like Record<string, T> so K extends string is the inferred type — every dot becomes a path-leg separator, letting an attacker traverse from the intended key into sibling and child fields the developer never meant to expose. The result is read access (and, in update statements, write access) to JSON sub-fields outside the intended scope across MySQL, PostgreSQL ->$/->>$, and SQLite. This vulnerability is fixed in 0.28.17.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Kysely versions 0.26.0-0.28.16 have a JSON path injection vulnerability where DefaultQueryCompiler.visitJSONPathLeg fails to escape metacharacters (., [, ], *, **, ?). When user-controlled input flows into .ref(col, '->$').key(input) or .at(input), attackers can traverse JSON paths to access sibling and child fields outside the intended scope, enabling unauthorized data exposure in SELECT and modification in UPDATE statements across MySQL, PostgreSQL, and SQLite.

MitigationUpgrade Kysely to version 0.28.17 or later. Audit all code using .key() and .at() with user-supplied input on JSON columns and validate/sanitize inputs until the upgrade is complete.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Kysely version
    Run 'npm list kysely' or check package.json dependencies to find the installed version number
    Affected if The version is 0.26.0 through 0.28.16 inclusive
  2. Search for .key() usage on JSON columns
    Search codebase for patterns like '.key(' or '.ref(' followed by '.key(' in your query building code
    Affected if Code uses .key() method with dynamic input on JSON column references
  3. Search for .at() usage on JSON columns
    Search codebase for patterns like '.at(' in JSON column query building code
    Affected if Code uses .at() method with dynamic input on JSON column references
  4. Audit user input to .key() and .at() calls
    Trace data flow from request parameters, body, or query strings into .key() or .at() method arguments
    Affected if User-supplied input directly or indirectly reaches these methods without validation

You are affected if Kysely version is between 0.26.0-0.28.16 AND your application uses .key() or .at() with untrusted user input on JSON columns in MySQL, PostgreSQL, or SQLite.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Kysely to version 0.28.17 or later. Audit all code using .key() and .at() with user-supplied input on JSON columns and validate/sanitize inputs until the upgrade is complete.

Recommended fix High confidence

0.28.17

  1. Check current Kysely version in package.json or by running npm list kysely or yarn list kysely
  2. Update package.json to specify kysely version ^0.28.17 or run npm install [email protected] (or yarn add [email protected])
  3. Run npm install or yarn install to update the dependency
  4. Verify the installed version is 0.28.17 or higher using npm list kysely or yarn list kysely
  5. Run existing test suite to ensure the upgrade does not break functionality
  6. If using TypeScript, rebuild the project (npm run build or tsc) to verify type compatibility

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing3.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,210
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-44635 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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