CVE-2026-25223Fastify's Content-Type header tab character allows body validation bypass
- 7.5HighCVSS base score
- 0.86%Exploitation in 30 daysEPSS · top 41% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By GitHub_M
- 4 days later
· 4 days later
Published
- 8 months later
· 8 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
| redhat-SADPADP (enrichment) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
- EPSS (exploitation in 30 days)
- 0.86% · top 41% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- npmfastifyGHSA-jx2c-rxcm-jvmq (opens in a new tab)
References
References12
- https://github.com/fastify/fastify/security/advisories/GHSA-jx2c-rxcm-jvmq (opens in a new tab)x_refsource_CONFIRM
- https://github.com/fastify/fastify/commit/32d7b6add39ddf082d92579a58bea7018c5ac821 (opens in a new tab)x_refsource_MISC
- https://hackerone.com/reports/3464114 (opens in a new tab)x_refsource_MISC
- https://fastify.dev/docs/latest/Reference/Validation-and-Serialization (opens in a new tab)x_refsource_MISC
- https://github.com/fastify/fastify/blob/759e9787b5669abf953068e42a17bffba7521348/lib/content-type-parser.js#L125 (opens in a new tab)x_refsource_MISC
- https://github.com/fastify/fastify/blob/759e9787b5669abf953068e42a17bffba7521348/lib/validation.js#L272 (opens in a new tab)x_refsource_MISC
- https://access.redhat.com/security/cve/CVE-2026-25223 (opens in a new tab)vdb-entryx_refsource_REDHAT
- RHBZ#2436560 (opens in a new tab)issue-trackingx_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-25223.json (opens in a new tab)x_sadp-csaf-vex
- https://access.redhat.com/errata/RHSA-2026:5807 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:10184 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:6192 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-5157 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-jx2c-rxcm-jvmq (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-25223)Record last updated .