Vulnerabilities in pkg:pypi/fastapi-sso

PACKAGE
Advisory Identifier: GHSA-hp6r-r9vc-q8wx
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Advisory Summary

CVE-2025-14546 is a MODERATE (CVSS 6.3) fastapi ssp is vulnerable to vulnerability (CWE-285: Improper Authorization) affecting Fastapi sso libraries in the PyPI ecosystem. The issue involves fastapi ssp is vulnerable to cross-site request forgery (csrf) through improper oauth parameter validation. Remediation is available by upgrading affected packages to version 0.19.0.

1 Known Advisory Record(s)
Package Vulnerability Intelligence

pkg:pypi/fastapi-sso

1 Known Advisory Record(s)

Vulnerability advisories affecting package pkg:pypi/fastapi-sso. Select an advisory below to view technical details or fixes.

Advisory ID CVE / NVD Severity Summary
GHSA-hp6r-r9vc-q8wx CVE-2025-14546 MODERATE FastAPI SSP is vulnerable to Cross-site Request Forgery (CSRF) through improper OAuth parameter validation

CVE-2025-14546 at a Glance

CVE Identifier CVE-2025-14546
GHSA Identifier GHSA-hp6r-r9vc-q8wx
Severity MODERATE
CVSS v3.1 Base Score 6.3
CWE Classification CWE-285: Improper Authorization
Affected Product Fastapi sso
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 6.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2025-14546

To remediate this vulnerability, upgrade all affected Fastapi sso dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

fastapi-sso fixed: 0.19.0 
pip install fastapi-sso>=0.19.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show fastapi-sso

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2025-14546, inspect your installed packages using pip:

pip show fastapi-sso

Analyze the terminal output to locate any version of Fastapi sso in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.19.0), your application is affected.

Note: The pip show fastapi-sso command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-285: Improper Authorization, where the product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. In Fastapi sso, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

Versions of the package fastapi-sso before 0.19.0 are vulnerable to Cross-site Request Forgery (CSRF) due to the improper validation of the OAuth state parameter during the authentication callback. While the get_login_url method allows for state generation, it does not persist the state or bind it to the user's session. Consequently, the verify_and_process method accepts the state received in the query parameters without verifying it against a trusted local value. This allows a remote attacker to trick a victim into visiting a malicious callback URL, which can result in the attacker's account being linked to the victim's internal account.

CVE-2025-14546 Affected Fastapi sso Versions

1 component(s)
Fixed Versions:
0.19.0
Product / Package Ecosystem Affected Versions Fixed Version
fastapi-sso
pypi/fastapi-sso
PyPI
< 0.19.0
0.19.0

References

Fastapi sso Security Information SECURITY
https://security.snyk.io/vuln/SNYK-PYTHON-FASTAPISSO-14386403
NVD — CVE-2025-14546 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-14546
Fastapi sso Source Repository REPOSITORY
https://github.com/tomasvotava/fastapi-sso/issues/266
Security Fix Commit FIX COMMIT
https://github.com/tomasvotava/fastapi-sso/commit/6117d1a5ad498ba57d671e8a059ebe20db5abe02
Fastapi sso Source Repository REPOSITORY
https://github.com/tomasvotava/fastapi-sso

Frequently Asked Questions

What is CVE-2025-14546?
CVE-2025-14546 is a security vulnerability in Fastapi sso involving FastAPI SSP is vulnerable to Cross-site Request Forgery (CSRF) through improper OAuth parameter validation under CWE-285: Improper Authorization.
Which Fastapi sso versions are affected?
Affected versions include releases prior to 0.19.0 across affected packages: fastapi-sso.
What version fixes CVE-2025-14546?
Upgrading to 0.19.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is fastapi-sso affected?
Yes, fastapi-sso is affected in releases prior to 0.19.0. Upgrade your dependency to 0.19.0 or later.
What is the CVSS score of CVE-2025-14546?
CVE-2025-14546 has a CVSS v3.1 base score of 6.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N.
What CWE is associated with CVE-2025-14546?
CVE-2025-14546 is classified under CWE-285: Improper Authorization (The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.).
How can I check PyPI dependencies for CVE-2025-14546?
Run the dependency tree command: 'pip show fastapi-sso'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-hp6r-r9vc-q8wx",
  "modified" : "2025-12-19T21:08:32Z",
  "published" : "2025-12-19T06:30:27Z",
  "aliases" : [ "CVE-2025-14546" ],
  "summary" : "FastAPI SSP is vulnerable to Cross-site Request Forgery (CSRF) through improper OAuth parameter validation",
  "details" : "Versions of the package fastapi-sso before 0.19.0 are vulnerable to Cross-site Request Forgery (CSRF) due to the improper validation of the OAuth state parameter during the authentication callback. While the get_login_url method allows for state generation, it does not persist the state or bind it to the user's session. Consequently, the verify_and_process method accepts the state received in the query parameters without verifying it against a trusted local value. This allows a remote attacker to trick a victim into visiting a malicious callback URL, which can result in the attacker's account being linked to the victim's internal account.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:P"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "fastapi-sso"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.19.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-14546"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/tomasvotava/fastapi-sso/issues/266"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/tomasvotava/fastapi-sso/commit/6117d1a5ad498ba57d671e8a059ebe20db5abe02"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/tomasvotava/fastapi-sso"
  }, {
    "type" : "WEB",
    "url" : "https://security.snyk.io/vuln/SNYK-PYTHON-FASTAPISSO-14386403"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-285" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-12-19T21:08:32Z",
    "nvd_published_at" : "2025-12-19T05:16:09Z"
  }
}