CVE-2025-66564
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-12-04

Last updated on: 2026-03-17

Assigner: GitHub, Inc.

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.
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Meta Information
Published
2025-12-04
Last Modified
2026-03-17
Generated
2026-06-16
AI Q&A
2025-12-05
EPSS Evaluated
2026-06-15
NVD
CVE-2025-66564
EUVD
EUVD-2025-201319
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linuxfoundation sigstore_timestamp_authority to 2.0.3 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-405 The product does not properly control situations in which an adversary can cause the product to consume or produce excessive resources without requiring the adversary to invest equivalent work or otherwise prove authorization, i.e., the adversary's influence is "asymmetric."
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Executive Summary

This vulnerability exists in the Sigstore Timestamp Authority service prior to version 2.0.3. The issue arises because the functions api.ParseJSONRequest and api.getContentType process untrusted input data by splitting strings (an OID and a Content-Type header, respectively) on certain characters. If a malicious request contains an excessively long OID with many periods or a malformed Content-Type header, these functions allocate memory proportional to the length of the input, potentially leading to excessive memory usage or resource exhaustion.

Impact Analysis

The vulnerability can lead to a denial of service condition by causing the Sigstore Timestamp Authority service to allocate large amounts of memory when processing maliciously crafted requests. This can degrade service availability or crash the service due to resource exhaustion.

Mitigation Strategies

Upgrade Sigstore Timestamp Authority to version 2.0.3 or later, as this version contains the fix for the vulnerability.

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