CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:NCVE-2026-25223
High (7.5) in fastify fastify. EPSS 0.9% chance of exploitation in the next 30 days. Fixed in fastify 5.7.2.
Fastify is a fast and low overhead web framework, for Node.js. Prior to version 5.7.2, a validation bypass vulnerability exists in Fastify where request body validation schemas specified by Content-Type can be completely circumvented. By appending a tab character (\t) followed by arbitrary content to the Content-Type header, attackers can bypass body validation while the server still processes the body as the original content type. This issue has been patched in version 5.7.2.
Severity
- EPSS
- 0.9% chance of exploitation in the next 30 days; higher than 58% of CVEs (scores of 2026-10-31)
- CWEs
- CWE-436, CWE-179
- Published
- Modified
- Record from
- the NVD, synced
Affected
- fastify:fastify
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-jx2c-rxcm-jvmq | npm | fastify | <5.7.2 | 5.7.2 |
References
- https://fastify.dev/docs/latest/Reference/Validation-and-Serialization
- https://github.com/fastify/fastify/blob/759e9787b5669abf953068e42a17bffba7521348/lib/content-type-parser.js#L125
- https://github.com/fastify/fastify/blob/759e9787b5669abf953068e42a17bffba7521348/lib/validation.js#L272
- https://github.com/fastify/fastify/commit/32d7b6add39ddf082d92579a58bea7018c5ac821
- https://github.com/fastify/fastify/security/advisories/GHSA-jx2c-rxcm-jvmq