fastify vulnerable to authentication bypass via malformed URLs reaching encapsulated not-found handlers
Collected exploitation and prediction evidence
Risk source coverageCISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.
No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.
cve-program · CVE-2026-76169
Publishedfastify 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.
- Source published
- 4 Sep 2026 09:51:03 UTC
- Source modified
- 4 Sep 2026 16:20:02 UTC
- Observed here
- 23 Oct 2026 15:48:27 UTC
- Source terms
- CVE Program Terms of Use
Original source record · Cite this exact observation · Complete original publisher JSON
This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.
CVSS 3.1 · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
euvd · EUVD-2026-70988
Publishedfastify 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.
EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.
Original publisher date fields
datePublished: Sep 4, 2026, 9:51:03 AM
dateUpdated: Sep 4, 2026, 4:20:02 PM
3 related source bulletins · separate from aliases
RHSA-2026:90321: Red Hat Security Advisory: Red Hat OpenShift Dev Spaces 3.31.0 Release.
CVE-2023-54404 · CVE-2025-62718 · CVE-2026-8643 · CVE-2026-9496 · CVE-2026-12185 · CVE-2026-13697 · CVE-2026-14682 · CVE-2026-15076 · CVE-2026-16308 · CVE-2026-17106 · CVE-2026-18427 · CVE-2026-19203 · CVE-2026-19534 · CVE-2026-39820 · CVE-2026-41178 · CVE-2026-41707 · CVE-2026-42499 · CVE-2026-42502 · CVE-2026-45416 · CVE-2026-47884 · CVE-2026-47886 · CVE-2026-47888 · CVE-2026-47890 · CVE-2026-47892 · CVE-2026-50010 · CVE-2026-55831 · CVE-2026-55833 · CVE-2026-55851 · CVE-2026-56745 · CVE-2026-56746 · CVE-2026-56819 · CVE-2026-56852 · CVE-2026-56854 · CVE-2026-58062 · CVE-2026-59280 · CVE-2026-59282 · CVE-2026-59283 · CVE-2026-59296 · CVE-2026-59313 · CVE-2026-59323 · CVE-2026-59651 · CVE-2026-59887 · CVE-2026-59899 · CVE-2026-59901 · CVE-2026-62243 · CVE-2026-64607 · CVE-2026-67213 · CVE-2026-67312 · CVE-2026-67313 · CVE-2026-67314 · CVE-2026-67320 · CVE-2026-67321 · CVE-2026-68494 · CVE-2026-68497 · CVE-2026-69152 · CVE-2026-69192 · CVE-2026-71290 · CVE-2026-71324 · CVE-2026-71325 · CVE-2026-71327 · CVE-2026-73500 · CVE-2026-73508 · CVE-2026-74835 · CVE-2026-75838 · CVE-2026-75899 · CVE-2026-75931 · CVE-2026-76169 · CVE-2026-81521 · CVE-2026-82417 · CVE-2026-82562 · CVE-2026-84292 · CVE-2026-84375 · CVE-2026-84394 · CVE-2026-84428 · CVE-2026-84445 · CVE-2026-84469 · CVE-2026-84504 · CVE-2026-84961 · CVE-2026-85062 · CVE-2026-85124 · CVE-2026-85152 · CVE-2026-85595 · CVE-2026-85597 · CVE-2026-86063 · CVE-2026-87743 · CVE-2026-88004 · CVE-2026-88007 · CVE-2026-88008 · CVE-2026-88009 · CVE-2026-88011 · CVE-2026-88012 · CVE-2026-88031 · CVE-2026-88878 · CVE-2026-88879 · CVE-2026-90711 · CVE-2026-93749 · CVE-2026-100655 · CVE-2026-100656 · CVE-2026-100666 · CVE-2026-101916 · CVE-2026-102925 · CVE-2026-102930 · CVE-2026-103435 · CVE-2026-109618 · CVE-2026-109619
RHSA-2026:87410: Red Hat Security Advisory: RHOAI 2.25.12 - Red Hat OpenShift AI
CVE-2024-12224 · CVE-2025-14920 · CVE-2025-14921 · CVE-2025-14924 · CVE-2025-14925 · CVE-2025-14926 · CVE-2025-14927 · CVE-2025-14928 · CVE-2025-14929 · CVE-2025-14930 · CVE-2025-61726 · CVE-2025-61729 · CVE-2026-5241 · CVE-2026-5497 · CVE-2026-6734 · CVE-2026-8643 · CVE-2026-9697 · CVE-2026-11822 · CVE-2026-11824 · CVE-2026-12151 · CVE-2026-12860 · CVE-2026-15143 · CVE-2026-15574 · CVE-2026-15679 · CVE-2026-15925 · CVE-2026-16221 · CVE-2026-18427 · CVE-2026-18446 · CVE-2026-18949 · CVE-2026-19481 · CVE-2026-19484 · CVE-2026-19534 · CVE-2026-25681 · CVE-2026-25960 · CVE-2026-27136 · CVE-2026-28390 · CVE-2026-28684 · CVE-2026-31812 · CVE-2026-32283 · CVE-2026-33186 · CVE-2026-33805 · CVE-2026-33811 · CVE-2026-33814 · CVE-2026-34993 · CVE-2026-39821 · CVE-2026-39852 · CVE-2026-39892 · CVE-2026-40682 · CVE-2026-41178 · CVE-2026-42502 · CVE-2026-42561 · CVE-2026-44431 · CVE-2026-44432 · CVE-2026-44660 · CVE-2026-44705 · CVE-2026-45820 · CVE-2026-47219 · CVE-2026-48526 · CVE-2026-48710 · CVE-2026-48746 · CVE-2026-49114 · CVE-2026-49825 · CVE-2026-49855 · CVE-2026-50559 · CVE-2026-54283 · CVE-2026-54399 · CVE-2026-54428 · CVE-2026-55831 · CVE-2026-55833 · CVE-2026-56121 · CVE-2026-56746 · CVE-2026-56819 · CVE-2026-56853 · CVE-2026-56858 · CVE-2026-56859 · CVE-2026-56860 · CVE-2026-56862 · CVE-2026-58059 · CVE-2026-59296 · CVE-2026-59879 · CVE-2026-59884 · CVE-2026-59885 · CVE-2026-59886 · CVE-2026-59899 · CVE-2026-62243 · CVE-2026-62384 · CVE-2026-63209 · CVE-2026-63374 · CVE-2026-65898 · CVE-2026-65918 · CVE-2026-66007 · CVE-2026-67213 · CVE-2026-67214 · CVE-2026-67312 · CVE-2026-68494 · CVE-2026-68497 · CVE-2026-68770 · CVE-2026-69097 · CVE-2026-69112 · CVE-2026-69152 · CVE-2026-69153 · CVE-2026-69243 · CVE-2026-69244 · CVE-2026-71281 · CVE-2026-73086 · CVE-2026-73088 · CVE-2026-73089 · CVE-2026-73415 · CVE-2026-73417 · CVE-2026-73502 · CVE-2026-73508 · CVE-2026-73620 · CVE-2026-73622 · CVE-2026-73623 · CVE-2026-73624 · CVE-2026-73625 · CVE-2026-73627 · CVE-2026-73646 · CVE-2026-75838 · CVE-2026-75899 · CVE-2026-75931 · CVE-2026-75975 · CVE-2026-76098 · CVE-2026-76169 · CVE-2026-76172 · CVE-2026-76222 · CVE-2026-76905 · CVE-2026-77354 · CVE-2026-77874 · CVE-2026-78676 · CVE-2026-78677 · CVE-2026-78679 · CVE-2026-78682 · CVE-2026-79674 · CVE-2026-79675 · CVE-2026-80205 · CVE-2026-81722 · CVE-2026-81724 · CVE-2026-81727 · CVE-2026-82397 · CVE-2026-82417 · CVE-2026-84292 · CVE-2026-84375 · CVE-2026-84394 · CVE-2026-84428 · CVE-2026-84445 · CVE-2026-84469 · CVE-2026-84504 · CVE-2026-84782 · CVE-2026-84961 · CVE-2026-85124 · CVE-2026-85152 · CVE-2026-85525 · CVE-2026-86049 · CVE-2026-86332 · CVE-2026-87776 · CVE-2026-87817 · CVE-2026-87819 · CVE-2026-88029 · CVE-2026-88031 · CVE-2026-89418 · CVE-2026-89425 · CVE-2026-91777 · CVE-2026-91990 · CVE-2026-92599 · CVE-2026-93599 · CVE-2026-93657 · CVE-2026-93749 · CVE-2026-96749 · CVE-2026-102831 · CVE-2026-102925 · CVE-2026-102930 · CVE-2026-102937 · CVE-2026-102938 · CVE-2026-103262 · CVE-2026-104851 · CVE-2026-105744
RHSA-2026:86891: Red Hat Security Advisory: RHOAI 3.5.2 - Red Hat OpenShift AI
CVE-2024-14029 · CVE-2026-13697 · CVE-2026-15679 · CVE-2026-15789 · CVE-2026-18427 · CVE-2026-19534 · CVE-2026-37237 · CVE-2026-49825 · CVE-2026-49855 · CVE-2026-54284 · CVE-2026-56859 · CVE-2026-59296 · CVE-2026-59893 · CVE-2026-62243 · CVE-2026-62384 · CVE-2026-63209 · CVE-2026-63374 · CVE-2026-66007 · CVE-2026-68494 · CVE-2026-68497 · CVE-2026-69097 · CVE-2026-69112 · CVE-2026-69152 · CVE-2026-69243 · CVE-2026-69244 · CVE-2026-71281 · CVE-2026-71491 · CVE-2026-73417 · CVE-2026-73502 · CVE-2026-73508 · CVE-2026-73646 · CVE-2026-75838 · CVE-2026-75899 · CVE-2026-75931 · CVE-2026-75975 · CVE-2026-76098 · CVE-2026-76169 · CVE-2026-76172 · CVE-2026-76222 · CVE-2026-76905 · CVE-2026-77354 · CVE-2026-77874 · CVE-2026-78676 · CVE-2026-78677 · CVE-2026-78679 · CVE-2026-78682 · CVE-2026-79674 · CVE-2026-79675 · CVE-2026-80205 · CVE-2026-81722 · CVE-2026-81724 · CVE-2026-81725 · CVE-2026-81726 · CVE-2026-81727 · CVE-2026-82397 · CVE-2026-82417 · CVE-2026-84292 · CVE-2026-84375 · CVE-2026-84381 · CVE-2026-84382 · CVE-2026-84394 · CVE-2026-84428 · CVE-2026-84445 · CVE-2026-84469 · CVE-2026-84504 · CVE-2026-84782 · CVE-2026-84961 · CVE-2026-85124 · CVE-2026-85152 · CVE-2026-85525 · CVE-2026-86332 · CVE-2026-87776 · CVE-2026-87817 · CVE-2026-87819 · CVE-2026-88029 · CVE-2026-88031 · CVE-2026-89425 · CVE-2026-91990 · CVE-2026-93348 · CVE-2026-93599 · CVE-2026-93657 · CVE-2026-93749 · CVE-2026-96749 · CVE-2026-96775 · CVE-2026-102925 · CVE-2026-102930 · CVE-2026-102937 · CVE-2026-102938 · CVE-2026-102990 · CVE-2026-104851 · CVE-2026-104852 · CVE-2026-104861 · CVE-2026-104873
- Source published
- Sep 4, 2026, 9:51:03 AM (timezone not stated)
- Source modified
- Sep 4, 2026, 4:20:02 PM (timezone not stated)
- Observed here
- 11 Nov 2026 16:07:26 UTC
- Source terms
- ENISA EUVD · source terms and attribution apply
Original source record · Cite this exact observation · Complete original publisher JSON
This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.
EUVD CVSS 3.1 · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
nvd · CVE-2026-76169
Publishedfastify 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.
NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.
Source analysis status: Analyzed
Weakness classifications: CWE-288
Original publisher date fields
published: 2026-09-04T10:17:12.020
lastModified: 2026-09-15T20:07:46.700
1 source CPE criteria · context only
- cpe:2.3:a:fastify:fastify:*:*:*:*:*:node.js:*:*
The original JSON retains the logical configuration operators, exclusions and version bounds.
- Source published
- 4 Sep 2026 10:17:12 UTC
- Source modified
- 15 Sep 2026 20:07:46 UTC
- Observed here
- 25 Oct 2026 16:19:04 UTC
- Source terms
- NIST NVD usage terms; underlying source attribution retained
Original source record · Cite this exact observation · Complete original publisher JSON
This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.
CVSS 3.1 · ce714d77-add3-4f53-aff5-83d477b104bb · Secondary · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
osv · GHSA-p68q-wchp-6fh7
Published### Impact Fastify routes a malformed URL under one plugin prefix to the custom not-found handler of a different sibling plugin, invoking the handler registered last and skipping the `preHandler` declared in its `setNotFoundHandler()`. When the request method has no route in the main router, a malformed request target reaches Fastify's internal not-found router before URL decoding and is dispatched through a single shared handler pointer, regardless of prefix and without the normal request lifecycle. An unauthenticated request to a public prefix can therefore reach an authentication-protected not-found handler registered under a different prefix and receive its full response, breaking prefix encapsulation and bypassing the authentication hook. Applications whose private or tenant fallbacks return protected data from a not-found handler are affected. ### Patches Patched in fastify 5.12.2. Malformed URLs are now routed through the configured `onBadUrl` and `onMaxParamLength` handlers so they fail closed before any application not-found handler runs, and the shared not-found handler pointer has been removed. ### Workarounds Reject malformed request targets before they reach the application, for example at an upstream proxy or gateway, and do not rely on a not-found handler to serve protected data. A global `onRequest` authentication hook does not mitigate this, because the malformed-URL path skips it.
- Source published
- 30 Sep 2026 23:45:34 UTC
- Source modified
- 1 Oct 2026 00:00:05 UTC
- Observed here
- 24 Oct 2026 13:17:17 UTC
- Source terms
- GitHub Advisory Database · CC-BY-4.0
Original source record · Cite this exact observation · Complete original publisher JSON
This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.
CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Publisher rating · HIGH