# CVE-2026-48763: TypeBot has Arbitrary S3 Object Write in deprecated public upload endpoint via attacker-controlled filePath

> Unauthenticated attackers can write arbitrary files to the shared S3 bucket via a deprecated public upload endpoint in TypeBot.

- **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Aug 2026
- **Updated:** 12 Aug 2026
- **Also known as:** GHSA-m7f5-3wcm-x2c4

## What is CVE-2026-48763?

CVE-2026-48763 is a high-severity missing authorization vulnerability in baptisteArno typebot.io, published on 11 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

TypeBot is a chatbot builder tool. Versions prior to 3.17.0 expose a deprecated public upload endpoint at `GET /api/v1/typebots/{typebotId}/blocks/{blockId}/storage/upload-url` that accepts an attacker-controlled `filePath` and returns a presigned S3 `PUT` URL for that exact key. Because the endpoint only checks that the referenced typebot is public and that the referenced block is a file input block, an unauthenticated attacker who knows a valid public `typebotId` and `blockId` can request presigned upload URLs for arbitrary objects in the shared bucket, including `private/...` and other tenants' `public/...` paths. Version 3.17.0 fixes this issue.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-48763?


## How do I fix CVE-2026-48763?

No fix has been published for CVE-2026-48763 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-48763 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-48763 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-48763 and fix it if it is affected.

What it is: CVE-2026-48763 is a high-severity missing authorization vulnerability in baptisteArno typebot.io, published on 11 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-48763 exists.

Affected product: baptisteArno typebot.io. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-48763/ (Markdown: https://insights.sbomify.com/CVE-2026-48763/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-48763
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-48763
- OSV: https://osv.dev/vulnerability/CVE-2026-48763

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-48763/
Summaries are generated and may contain mistakes; the official description above is the record.