Sigstore Timestamp Authority is a service for issuing RFC 3161 timestamps. Prior to 2.0.3, Function api.ParseJSONRequest currently splits (via a call to strings.Split) an optionally-provided OID (which is untrusted data) on periods. Similarly, function api.getContentType splits the Content-Type header (which is also untrusted data) on an application string. As a result, in the face of a malicious request with either an excessively long OID in the payload containing many period characters or a malformed Content-Type header, a call to api.ParseJSONRequest or api.getContentType incurs allocations of O(n) bytes (where n stands for the length of the function's argument). This vulnerability is fixed in 2.0.3.

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00017.

Exploitation none

Automatable yes

Technical Impact partial

Affected Vendors & Products

Vendors Products
Sigstore Subscribe
Timestamp Authority Subscribe

No data.

No data.

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Vendors Products
Sigstore Subscribe
Timestamp Authority Subscribe
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-4qg8-fj49-pxjh Sigstore Timestamp Authority allocates excessive memory during request parsing
Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/sigstore/timestamp-authority/commit/0cae34e197d685a14904e0bad135b89d13b69421 cve-icon cve-icon cve-icon
https://github.com/sigstore/timestamp-authority/security/advisories/GHSA-4qg8-fj49-pxjh cve-icon cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2025-66564 cve-icon
https://www.cve.org/CVERecord?id=CVE-2025-66564 cve-icon
History

Thu, 11 Dec 2025 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

 threat_severity

Important

Fri, 05 Dec 2025 15:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Fri, 05 Dec 2025 11:00:00 +0000

Type Values Removed Values Added
First Time appeared Sigstore
Sigstore timestamp Authority
Vendors & Products Sigstore
Sigstore timestamp Authority

Thu, 04 Dec 2025 22:45:00 +0000

Type Values Removed Values Added
Description Sigstore Timestamp Authority is a service for issuing RFC 3161 timestamps. Prior to 2.0.3, Function api.ParseJSONRequest currently splits (via a call to strings.Split) an optionally-provided OID (which is untrusted data) on periods. Similarly, function api.getContentType splits the Content-Type header (which is also untrusted data) on an application string. As a result, in the face of a malicious request with either an excessively long OID in the payload containing many period characters or a malformed Content-Type header, a call to api.ParseJSONRequest or api.getContentType incurs allocations of O(n) bytes (where n stands for the length of the function's argument). This vulnerability is fixed in 2.0.3.
Title Sigstore Timestamp Authority allocates excessive memory during request parsing
Weaknesses CWE-405
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2025-12-05T14:55:53.273Z

Reserved: 2025-12-04T16:05:22.975Z

Link: CVE-2025-66564

cve-icon Vulnrichment

Updated: 2025-12-05T14:55:50.449Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-12-04T23:15:47.430

Modified: 2025-12-08T18:27:15.857

Link: CVE-2025-66564

cve-icon Redhat

Severity : Important

Publid Date: 2025-12-04T22:37:13Z

Links: CVE-2025-66564 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2025-12-05T10:52:19Z

Weaknesses