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TI-2026-19675 Aliases CVE-2026-24408GHSA-hm8f-75xx-w2vr

sigstore has CSRF possibility in OIDC authentication during signing

Priority LOW 22CWE-352Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
High
Impact type
Tampering
Confidentiality · integrity · availability
Low · Low · Low
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-352.

Summary

sigstore-python is a Python tool for generating and verifying Sigstore signatures. Prior to version 4.2.0, the sigstore-python OAuth authentication flow is susceptible to Cross-Site Request Forgery. `_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. Version 4.2.0 contains a patch for the issue.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00178 7th percentileScored 2026-11-07
Fix Fixed sigstore-python (sigstore): 4.2.0sigstore (PyPI): 4.2.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
sigstoresigstore-pythonbefore 4.2.04.2.0Patch availableCNA
—sigstore (PyPI)before 4.2.04.2.0Patch availableGHSA-hm8f-75xx-w2vr
  • sigstore-python Vendorsigstore Affected before 4.2.0 Fixed in 4.2.0 Patch available CNA
  • sigstore (PyPI) Vendor— Affected before 4.2.0 Fixed in 4.2.0 Patch available GHSA-hm8f-75xx-w2vr

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:linuxfoundation:sigstore-python:*:*:*:*:*:*:*:*before 4.2.0Vulnerablebackstage
  • cpe:2.3:a:linuxfoundation:sigstore-python:*:*:*:*:*:*:*:* Versions before 4.2.0 Vulnerable ·backstage

Remediation

  • Fix · CNA sigstore-python (sigstore) Fixed in 4.2.0
  • Fix · GHSA-hm8f-75xx-w2vr sigstore (PyPI) Fixed in 4.2.0 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-24408
  2. 2026-10-03 Alias added: GHSA-hm8f-75xx-w2vr

References

Patch 1

Advisory 2

Other 2

  • TI-2022-16356 False positive signature verification in cosign CVSS 3.1CRITICAL 9.8
  • TI-2026-36084 sigstore-js: `certificateOIDs` verification constraints are silently dropped and never enforced CVSS 3.1HIGH 7.5
  • TI-2024-19670 Cosign vulnerable to machine-wide denial of service via malicious artifacts CVSS 3.1HIGH 7.5
  • TI-2026-18290 Fulcio vulnerable to Server-Side Request Forgery (SSRF) via MetaIssuer Regex Bypass CVSS 3.1MEDIUM 5.8
  • TI-2026-36085 sigstore-js: Insufficient Verification of Data Authenticity CVSS 3.1MEDIUM 6.5
  • TI-2024-19669 Cosign vulnerable to system-wide denial of service via malicious attachments CVSS 3.1MEDIUM 5.9
See all 39 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences