Summary
sigstore CSRF possibility in OIDC authentication during signing
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.
A victim's authenticated browser session is used to submit forged requests to an application that cannot distinguish them from legitimate ones. Typical impact: state-changing actions performed as the victim without their consent.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2026-24408? CVE-2026-24408 is a low-severity cross-site request forgery (CSRF) vulnerability in sigstore (pip), affecting versions < 4.2.0. It is fixed in 4.2.0. A victim's authenticated browser session is used to submit forged requests to an application that cannot distinguish them from legitimate ones.
- Which versions of sigstore are affected by CVE-2026-24408? sigstore (pip) versions < 4.2.0 is affected.
- Is there a fix for CVE-2026-24408? Yes. CVE-2026-24408 is fixed in 4.2.0. Upgrade to this version or later.
- Is CVE-2026-24408 exploitable, and should I be worried? Whether CVE-2026-24408 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-24408 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-24408? Upgrade
sigstoreto 4.2.0 or later.