Medium severity · published Jan 26, 2026
CVE-2026-24408
sigstore has CSRF possibility in OIDC authentication during signing
5.0
CVSS
0.2%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L
Attack vector
Network
Complexity
High
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 7% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SI
sigstore-python · sigstore
< 4.2.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-24408
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-24408
Patch
https://github.com/sigstore/sigstore-python/commit/5e77497fe8f0b202bdd118949074ec2f20da69aa
Product
https://github.com/sigstore/sigstore-python/releases/tag/v4.2.0
Vendor Advisory
https://github.com/sigstore/sigstore-python/security/advisories/GHSA-hm8f-75xx-w2vr