# CVE-2026-114620: Authlib: Unvalidated request_uri fetch in JWT-secured authorization request (JAR) leading to SSRF


- **Severity:** Medium 5.4 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 22 Oct 2026
- **Updated:** 22 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-114620, ECHO-567b-5cd2-78a6, GHSA-x4rv-c3wx-4cr8, MINI-jrqr-f4v2-r686, UBUNTU-CVE-2026-114620

## What is CVE-2026-114620?

CVE-2026-114620 is a medium-severity vulnerability in authlib, published on 22 Oct 2026. 

### Official description

Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.9.0, Authlib's RFC 9101 JWTAuthenticationRequest passes the unauthenticated, client-controlled request_uri parameter to the abstract get_request_object() hook before applying a destination or registration policy; the hook itself performs no network request, while the documentation demonstrates an unrestricted HTTP fetch. In deployments whose integrator implements that hook as an unrestricted outbound fetch, a remote attacker who knows a valid public client identifier can make the authorization server request internal, link-local, or otherwise unintended URLs and can distinguish fetch outcomes through different error responses and timing. Deployments whose custom hook already applies a secure allowlist, destination controls, and retrieval limits are not affected. The JWTAuthenticationRequest implementation in authlib/oauth2/rfc9101/authorization_server.py forwards request_uri to get_request_object() before an application-approved retrieval policy accepts the destination. This issue is fixed in version 1.9.0.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-114620?

2 open source packages ship an affected version, including authlib. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `authlib` | PyPI | From 1.6.0 | 1.9.0 |
| `authlib` | PyPI | From 1.6.0 | 1.9.0 |

Products: Authlib Authlib.

## How do I fix CVE-2026-114620?

Upgrade authlib to 1.9.0 or later.

## Is CVE-2026-114620 being exploited?

There is no known exploitation of CVE-2026-114620 in the wild and no public exploit code.

## Other vulnerabilities in authlib

- [CVE-2026-27962](https://insights.sbomify.com/CVE-2026-27962/): Authlib JWS JWK Header Injection: Signature Verification Bypass (critical 9.1)
- [CVE-2026-28490](https://insights.sbomify.com/CVE-2026-28490/): Authlib Vulnerable to JWE RSA1_5 Bleichenbacher Padding Oracle (high 8.3)
- [CVE-2026-28498](https://insights.sbomify.com/CVE-2026-28498/): Authlib: Fail-Open Cryptographic Verification in OIDC Hash Binding (high 8.2)
- [CVE-2026-28802](https://insights.sbomify.com/CVE-2026-28802/): Authlib: Setting `alg: none` and a blank signature appears to bypass signature verification (high 7.7)
- [CVE-2025-61920](https://insights.sbomify.com/CVE-2025-61920/): Authlib is vulnerable to Denial of Service via Oversized JOSE Segments (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-114620 and fix it if it is affected.

What it is: CVE-2026-114620 is a medium-severity vulnerability in authlib, published on 22 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-114620 in the wild and no public exploit code.

Affected packages and fixed versions:
- authlib (PyPI): affected from 1.6.0; fixed in 1.9.0
- authlib (PyPI): affected from 1.6.0; fixed in 1.9.0

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-2026-114620/ (Markdown: https://insights.sbomify.com/CVE-2026-114620/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-114620
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-114620
- OSV: https://osv.dev/vulnerability/CVE-2026-114620

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-114620/
Summaries are generated and may contain mistakes; the official description above is the record.