Asymmetric Resource Consumption (Amplification) Affecting cosign package, versions <3.0.3-r0


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.02% (5th percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-COSIGN-14422174
  • published15 Dec 2025
  • disclosed4 Dec 2025

Introduced: 4 Dec 2025

CVE-2025-66564  (opens in a new tab)
CWE-405  (opens in a new tab)

How to fix?

Upgrade Chainguard cosign to version 3.0.3-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream cosign package and not the cosign package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1