---
id: CVE-2026-24408
aliases:
  - GHSA-hm8f-75xx-w2vr
  - PYSEC-2026-1924
title: sigstore CSRF possibility in OIDC authentication during signing
summary: sigstore CSRF possibility in OIDC authentication during signing
severity: none
cvss: 0
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:N'
vendor: sigstore
product: sigstore
ecosystem: pip
affected:
  - sigstore < 4.2.0
patched:
  - sigstore 4.2.0
published: '2026-01-26'
updated: '2026-07-07'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-hm8f-75xx-w2vr'
references:
  - url: >-
      https://github.com/sigstore/sigstore-python/security/advisories/GHSA-hm8f-75xx-w2vr
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-24408'
  - url: >-
      https://github.com/sigstore/sigstore-python/commit/5e77497fe8f0b202bdd118949074ec2f20da69aa
  - url: 'https://github.com/sigstore/sigstore-python'
  - url: 'https://github.com/sigstore/sigstore-python/releases/tag/v4.2.0'
tags:
  - osv
  - pip
epss: 0.00181
epssPercentile: 0.06803
ingestedAt: '2026-07-08T18:25:50.280Z'
---

## Overview

### Summary

The sigstore-python OAuth authentication flow is susceptible to Cross-Site Request Forgery.

### Details

`_OAuthSession` creates a unique "state" and sends it as a parameter in the authentication request but the "state" in the server response seems not not be cross-checked with this value. 

Fix should be fairly trivial.

### Impact

This should be low impact: A man-in-the middle attacker could trick a sigstore-python user into signing something with an identity controlled by the attacker (by returning the response to an authentication request they created). This would be quite confusing but not dangerous.

## Affected packages

- `sigstore < 4.2.0`

## Remediation

Upgrade to a patched release:

- `sigstore 4.2.0`