StarletteApplication · Encode
CVE-2026-48817
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedStarlette is a lightweight ASGI framework/toolkit. In versions 1.0.1 and below, when dispatching a request, HTTPEndpoint selects the handler by lowercasing the HTTP method and looking it up as an attribute with getattr, without restricting the lookup to a known set of HTTP verbs. When an HTTPEndpoint subclass is registered through Route(...) without an explicit methods= argument, the route does not constrain the method and every method reaches the endpoint. If a non-standard HTTP method whose lowercased name matches an attribute on the endpoint subclass reaches the endpoint, that attribute is invoked as if it were a request handler. An attacker can use this to reach methods that were never meant to be HTTP handlers, such as internal helpers, without the authorization checks applied by the intended public handler. An application (including Starlette-based frameworks like FastAPI) is affected if it registers an HTTPEndpoint subclass via Route(...) without explicitly setting methods=, and that subclass includes extra methods named like non-standard HTTP verbs that take one request argument and return a response. This issue has been fixed in version 1.1.0.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceIn Starlette 1.0.1 and below, HTTPEndpoint dispatches requests by lowercasing the HTTP method and using getattr to find a matching attribute handler without restricting to standard HTTP verbs. When Route(...) is used without explicit methods= argument, any method can reach the endpoint. If a non-standard HTTP method name matches an attribute on the endpoint subclass (like an internal helper method), it gets invoked as an HTTP handler, bypassing authorization checks intended for the proper public handlers.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
StarletteApplication
< 1.1.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check installed Starlette versionRun `pip show starlette` or `python -c "import starlette; print(starlette.__version__)"`Affected if Version is below 1.1.0 (e.g., 1.0.1 or earlier)
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Find Route definitions missing methods parameterSearch your codebase for Route( declarations that lack a methods= argument, for example: `Route("/path", MyEndpoint)` without specifying methods=["GET"]Affected if Any Route(...) is defined without explicit methods= parameter
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Identify HTTPEndpoint subclassesSearch for class definitions inheriting from HTTPEndpoint, for example: `class MyEndpoint(HTTPEndpoint):`Affected if Your codebase contains classes that subclass HTTPEndpoint
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Inspect HTTPEndpoint subclasses for potential internal methodsReview each HTTPEndpoint subclass for attributes or methods that could be accidentally exposed - look for any public methods or attributes (excluding standard HTTP verbs like get, post, put, delete, patch) that could match a non-standard HTTP method nameAffected if An HTTPEndpoint subclass has methods/attributes with names that are not standard HTTP verbs and could be invoked via a crafted request
You are affected if Starlette version is below 1.1.0 AND you have Route(...) registrations without explicit methods= combined with HTTPEndpoint subclasses that have non-standard method names vulnerable to being dispatched.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped1.1.0
Upgrade Starlette to version 1.1.0 or later, and audit all Route(...) registrations to ensure methods= is explicitly specified to constrain allowed HTTP methods.
1.1.0
- Update the Starlette package to version 1.1.0 or later using your package manager (e.g., pip install starlette>=1.1.0)
- If using FastAPI or another framework that depends on Starlette, ensure its compatible version is installed
- After upgrading, verify that any HTTPEndpoint subclasses with custom methods are not inadvertently exposed as handlers by explicitly specifying methods= argument in Route(...) or reviewing endpoint method naming
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Starlette
Scoped from the published advisory
- Consultation2.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,696.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-48817 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-48817 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
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