CVE-2026-76169
- Source
- https://cve.org/CVERecord?id=CVE-2026-76169
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-76169.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-76169
- Aliases
- Downstream
CLSA (6)
MINI (1)
- Published
- 2026-09-04T09:51:03Z
- Modified
- 2026-10-21T02:59:40Z
- Severity
-
- 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N CVSS Calculator
- Summary
- fastify vulnerable to authentication bypass via malformed URLs reaching encapsulated not-found handlers
- Details
-
fastify versions >= 4.0.0 and before 5.12.2 can route a malformed URL sent under one plugin prefix to the custom not-found handler of a different sibling plugin, and invoke it without the preHandler hook declared for that handler. The internal not-found router for encapsulated handlers dispatches malformed paths through a single shared handler pointer before URL decoding, ignoring the prefix and skipping the selected handler's normal lifecycle. An unauthenticated attacker can therefore reach an authentication-protected private fallback through an unrelated public prefix and read its full response, bypassing the authentication hook and breaking prefix encapsulation. Users should upgrade to fastify 5.12.2 or later.
- Database specific
{ "cna_assigner": "openjs", "cwe_ids": [ "CWE-288" ], "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/76xxx/CVE-2026-76169.json" }- References
Affected packages
Git / github.com/fastify/fastify
Affected ranges
- Type
- GIT
- Repo
- https://github.com/fastify/fastify
- Events
- Database specific
-
Show details
{ "extracted_events": [ { "range": [ { "introduced": "4.0.0" }, { "fixed": "5.12.2" } ], "source": "AFFECTED_FIELD", "strategy": "StandardRange" }, { "cpe": "cpe:2.3:a:fastify:fastify:*:*:*:*:*:node.js:*:*", "range": [ { "introduced": "4.0.0" }, { "fixed": "5.12.2" } ], "source": "CPE_RANGE" } ] }
Affected versions
v4.*
v4.0.0
v4.0.1
v4.0.2
v4.0.3
v4.1.0
v4.2.0
v4.2.1
v4.3.0
v4.4.0
v4.5.0
v4.5.1
v4.5.2
v5.*
v5.0.0
v5.0.0-alpha.1
v5.0.0-alpha.2
v5.0.0-alpha.4
v5.1.0
v5.10.0
v5.11.0
v5.11.1
v5.11.2
v5.11.3
v5.12.0
v5.12.1
v5.2.0
v5.2.1
v5.2.2
v5.3.0
v5.3.1
v5.3.2
v5.3.3
v5.4.0
v5.5.0
v5.6.0
v5.6.1
v5.6.2
v5.7.0
v5.7.1
v5.7.2
v5.7.3
v5.7.4
v5.8.0
v5.8.1
v5.8.2
v5.8.3
v5.8.4
v5.8.5
v5.9.0