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.

Exploitation none

Automatable yes

Technical Impact partial

Affected Vendors & Products

Vendors Products
Linuxfoundation
  • Sigstore Timestamp Authority
Sigstore
  • Timestamp Authority

Configuration 1 [-]

cpe:2.3:a:linuxfoundation:sigstore_timestamp_authority:*:*:*:*:*:*:*:*

No data.

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

Tue, 17 Mar 2026 20:45:00 +0000

Type Values Removed Values Added
First Time appeared Linuxfoundation
Linuxfoundation sigstore Timestamp Authority
CPEs cpe:2.3:a:linuxfoundation:sigstore_timestamp_authority:*:*:*:*:*:*:*:*
Vendors & Products Linuxfoundation
Linuxfoundation sigstore Timestamp Authority

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'}
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2025-12-04T22:37:13.307Z

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 : Analyzed

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

Modified: 2026-03-17T20:38:33.343

Link: CVE-2025-66564

cve-icon Redhat

Severity : Important

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

Links: CVE-2025-66564 - Bugzilla