sigstore CSRF possibility in OIDC authentication during signing

CVE-2026-24408 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

Description

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.

Basic information

Type
reviewed
Severity
low
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2026-01-26 21:34:50 UTC
Updated
2026-01-29 03:24:34 UTC
GitHub reviewed
2026-01-26 21:34:50 UTC
NVD published
2026-01-26

EPSS Score

Score Percentile
0.01% 0.44%

CVSS Scores

Base score Version Severity Vector
— 3.1 —
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.

Identifiers

Type Value
GHSA GHSA-hm8f-75xx-w2vr ↗
CVE CVE-2026-24408 ↗

CWEs

CWE id Name
CWE-352 Cross-Site Request Forgery (CSRF)

Credits

  • jku (reporter)

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
pip sigstore < 4.2.0 4.2.0 —

References

cvelogic Threat Intelligence