id: PYSEC-2026-1924
published: "2026-07-07T16:03:20.418491Z"
modified: "2026-07-07T17:25:24.106990Z"
aliases:
- CVE-2026-24408
- GHSA-hm8f-75xx-w2vr
summary: sigstore CSRF possibility in OIDC authentication during signing
details: "### Summary\n\nThe sigstore-python OAuth authentication flow is susceptible to Cross-Site Request Forgery.\n\n### Details\n\n`_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. \n\nFix should be fairly trivial.\n\n### Impact\n\nThis 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:
- package:
    name: sigstore
    ecosystem: PyPI
    purl: pkg:pypi/sigstore
  ranges:
  - type: ECOSYSTEM
    events:
    - introduced: "0"
    - fixed: 4.2.0
  versions:
  - 0.0.1rc1
  - 0.0.1rc2
  - 0.0.1rc3
  - 0.1.0
  - 0.10.0
  - 0.2.0
  - 0.3.1
  - 0.4.0
  - 0.4.1
  - 0.4.2
  - 0.5.0
  - 0.5.1
  - 0.5.1rc1
  - 0.5.1rc2
  - 0.6.1
  - 0.6.2
  - 0.6.3
  - 0.6.4
  - 0.6.5
  - 0.6.6
  - 0.6.7
  - 0.6.8
  - 0.7.0
  - 0.8.3
  - 0.9.0
  - 1.0.0
  - 1.0.0rc1
  - 1.1.0
  - 1.1.1
  - 1.1.1rc1
  - 1.1.2
  - 1.1.2rc1
  - 2.0.0
  - 2.0.0rc1
  - 2.0.0rc2
  - 2.0.0rc3
  - 2.0.1
  - 2.1.0
  - 2.1.2
  - 2.1.3
  - 2.1.5
  - 3.0.0
  - 3.0.0rc1
  - 3.0.0rc2
  - 3.1.0
  - 3.2.0
  - 3.3.0
  - 3.4.0
  - 3.5.0
  - 3.5.1
  - 3.5.3
  - 3.5.6
  - 3.6.0
  - 3.6.1
  - 3.6.2
  - 3.6.3
  - 3.6.4
  - 3.6.5
  - 3.6.6
  - 3.6.7
  - 4.0.0
  - 4.1.0
references:
- type: WEB
  url: https://github.com/sigstore/sigstore-python/security/advisories/GHSA-hm8f-75xx-w2vr
- type: ADVISORY
  url: https://nvd.nist.gov/vuln/detail/CVE-2026-24408
- type: WEB
  url: https://github.com/sigstore/sigstore-python/commit/5e77497fe8f0b202bdd118949074ec2f20da69aa
- type: PACKAGE
  url: https://github.com/sigstore/sigstore-python
- type: WEB
  url: https://github.com/sigstore/sigstore-python/releases/tag/v4.2.0
- type: PACKAGE
  url: https://pypi.org/project/sigstore
- type: ADVISORY
  url: https://github.com/advisories/GHSA-hm8f-75xx-w2vr
severity:
- type: CVSS_V3
  score: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:N