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HonoApplication

CVE-2026-44457

MEDIUM · 5.3 CVSS v3.1 Published 2026-05-13
Fix available
A fix is available. Upgrade to 4.12.18 or later.
See remediation →
62/100
Remediation priority · Elevated
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
Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.18, Cache Middleware does not skip caching for responses that declare per-user variance via Vary: Authorization or Vary: Cookie. As a result, a response cached for one authenticated user may be served to subsequent requests from different users. This vulnerability is fixed in 4.12.18.

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

The Hono framework's Cache Middleware before version 4.12.18 fails to respect Vary: Authorization and Vary: Cookie headers, which indicate that responses are user-specific. This causes responses for one authenticated user to be incorrectly cached and served to subsequent requests from different users, leading to potential information disclosure.

MitigationUpgrade Hono to version 4.12.18 or later to obtain the fixed Cache Middleware that properly handles Vary headers. Verify that caching behavior works correctly after the update.

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

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
HonoApplication
Affected:< 4.12.18

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
Low
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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. Check installed Hono version
    Run 'npm list hono' or inspect package.json to see the installed version of the hono package
    Affected if Version is lower than 4.12.18
  2. Verify Cache Middleware is in use
    Search your source code for 'import { cache }' or 'new Cache()' usage from the hono package
    Affected if Cache Middleware is imported and used in your application code
  3. Confirm caching is enabled
    Review your application configuration and middleware setup to determine if caching is actively configured for routes
    Affected if Caching is enabled and applied to routes that handle user-specific content
  4. Inspect Vary header handling
    Check your application's response headers or code that sets Vary headers. Look for 'Vary: Authorization' or 'Vary: Cookie' headers being set on cached endpoints
    Affected if Your cached endpoints serve user-specific content but do not properly set Vary: Authorization or Vary: Cookie headers in responses
  5. Test cache behavior with different users
    Make a request as user A to a cached endpoint, then make a request as user B to the same endpoint and compare responses
    Affected if User B receives content that was generated for user A, indicating cached responses are being shared across users

You are affected if Hono version is below 4.12.18, Cache Middleware is enabled, and your application caches responses for authenticated or user-specific endpoints without properly handling Vary: Authorization or Vary: Cookie headers.

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
Upgrade available Upgrade to 4.12.18 or later
Fixed in 4.12.18
Interim mitigation

Upgrade Hono to version 4.12.18 or later to obtain the fixed Cache Middleware that properly handles Vary headers. Verify that caching behavior works correctly after the update.

Recommended fix High confidence

4.12.18

  1. Update your package.json to specify [email protected], or run `npm install [email protected]` (or yarn/pnpm equivalent)
  2. Run `npm install` to install the updated dependency
  3. Verify the installed version matches 4.12.18 by checking node_modules/hono/package.json
  4. Test your application to ensure the cache middleware functions correctly with the new version

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

Fix this in Hono Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing3.0 h
  • Review / QA2.0 h
8.0 hours of engineering $1,390
Get the upgrade done

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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-2026-44457 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data