PT-2026-39327 · Hono · Hono

Published

2026-05-09

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Updated

2026-05-18

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CVE-2026-44457

CVSS v3.1

5.3

Medium

VectorAV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Name of the Vulnerable Software and Affected Versions Hono versions prior to 4.12.18
Description Cache Middleware fails to skip caching for responses that declare per-user variance using the Vary: Authorization or Vary: Cookie headers. While the middleware correctly skips caching for Vary: *, Set-Cookie, and specific Cache-Control directives such as private, no-store, or no-cache, it does not recognize Vary: Authorization and Vary: Cookie as reasons to avoid caching. This occurs when applications use Cache Middleware on endpoints returning user-specific data and rely on these headers to scope responses without also setting Cache-Control: private. Consequently, a response cached for one authenticated user may be served to subsequent requests from different users, potentially leading to the disclosure of personally identifiable information or other user-specific data.
Recommendations Update to version 4.12.18. As a temporary workaround, ensure that endpoints returning user-specific data set the Cache-Control: private header to prevent incorrect caching.

Fix

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Weakness Enumeration

Related Identifiers

CLEANSTART-2026-BE61221
CVE-2026-44457
GHSA-P77W-8QQV-26RM

Affected Products

Hono