CVE-2026-24408
sigstore has CSRF possibility in OIDC authentication during signing
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
sigstore has CSRF possibility in OIDC authentication during signing
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.
- Record
CVE-2026-24408- CVSS 3.1
- 0.0 None
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:N - Weakness
- CWE-352
- Updated
- 2026-11-02
EUVDEUVD-2026-4729 No score
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.
- Record
EUVD-2026-4729- Updated
- 2026-11-02
GitHub AdvisoriesGHSA-hm8f-75xx-w2vr
sigstore CSRF possibility in OIDC authentication during signing
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.
- Record
GHSA-hm8f-75xx-w2vr- CVSS 3.1
- 0.0 None
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:N - Weakness
- CWE-352
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-24408- CVSS 3.1
- 0.0 None
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:N - CVSS 3.1
- 5.0 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L - Weakness
- CWE-352
- Updated
- 2026-11-02
OSV
sigstore has CSRF possibility in OIDC authentication during signing
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.
- Record
CVE-2026-24408- CVSS 3.1
- 0.0 None
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:N - Weakness
- CWE-352
- Updated
- 2026-11-02
OSVGHSA-hm8f-75xx-w2vr
sigstore CSRF possibility in OIDC authentication during signing
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.
- Record
GHSA-hm8f-75xx-w2vr- CVSS 3.1
- 0.0 None
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:N - Weakness
- CWE-352
- Updated
- 2026-11-02
OSVPYSEC-2026-1924
sigstore CSRF possibility in OIDC authentication during signing
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.
- Record
PYSEC-2026-1924- CVSS 3.1
- 0.0 None
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:N - Updated
- 2026-11-02
OSVopenSUSE-SU-2026:10104-1 No score
python311-sigstore-4.2.0-1.1 on GA media
These are all security issues fixed in the python311-sigstore-4.2.0-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2026:10104-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
sigstorePyPI |
before 4.2.0 | 4.2.0 |
sigstorePyPI |
before 4.2.0, plus listed versions 0.0.1rc10.0.1rc20.0.1rc30.1.00.10.0 Show 45 moreShow less0.2.00.3.10.4.00.4.10.4.20.5.00.5.10.5.1rc10.5.1rc20.6.10.6.20.6.30.6.40.6.50.6.60.6.70.6.80.7.00.8.30.9.01.0.01.0.0rc11.1.01.1.11.1.1rc11.1.21.1.2rc12.0.02.0.0rc12.0.0rc22.0.0rc32.0.12.1.02.1.22.1.32.1.53.0.03.0.0rc13.0.0rc23.1.03.2.03.3.03.4.03.5.03.5.1 |
4.2.0 |
python-sigstoreopenSUSE:Tumbleweed |
before 4.2.0-1.1 | 4.2.0-1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-24408 is a none vulnerability (CVSS 0.0) in Linuxfoundation Sigstore-python, published January 26, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.18%, the 7th percentile. Fixed in sigstore 4.2.0.
References
github.com/sigstore/sigstore-python/security/advisories/GHSA-hm8f-75xx-w2vr
nvd.nist.gov/vuln/detail/CVE-2026-24408
pypi.org/project/sigstore
suse.com/security/cve/CVE-2026-24408
Left out here: 12 versions. The JSON record has them.