CVE-2026-107832 (GCVE-0-2026-107832)

Vulnerability from cvelistv5 – Published: 2026-10-13 13:23 – Updated: 2026-10-13 13:23
VLAI
Title
fastify vulnerable to header validation bypass via case-sensitive propertyNames
Summary
fastify is a fast and low overhead web framework for Node.js. In versions 5.12.2 through 5.12.5, the routine that lowercases header names declared in a route schema does not lowercase the enum or const header names nested inside a propertyNames subschema. As a result, a header allow-list or deny-list written with canonical (non-lowercase) casing never matches the incoming lowercased header, so a restricted header passes validation and reaches the route handler. An attacker can therefore bypass a case-sensitive header validation rule and smuggle a forbidden header past the schema, affecting the integrity of request handling. The issue is fixed in fastify 5.12.6, and users should upgrade to 5.12.6 or later. There is no workaround other than upgrading, though applications can declare header names in lowercase to avoid the mismatch.
Severity
3.7 (Low)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
CWE
  • CWE-178 - Improper Handling of Case Sensitivity
Assigner
openjs CNA under the redhat root
CNA scorecard C 65/100 over 99 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
fastify fastify Affected: 5.12.2 , < 5.12.6 (semver)
Unaffected: 5.12.6 (semver)
guessed Create a notification for this product.
Credits
uttej-badwane mcollina UlisesGascon kian0417
Show details on NVD website
To clipboard 

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