Fulcio allocates excessive memory during token parsing

高 7.5CVE-2025-66506 · GHSA-f83f-xpx7-ffpw · GO-2025-4193 · 04/12/2025 公開 · 18/10/2026 更新

要点

CVE-2025-66506 は github.com/sigstore/fulcio, fulcio (linuxfoundation) に影響する深刻度「高」 (CVSS 7.5) の脆弱性です。
今後30日間に悪用される確率（EPSS）：0.21%（全脆弱性の 11.3% より高い）。
対処：1.8.3 以降に更新してください。

パッケージ	影響を受けるバージョン	修正済みバージョン
github.com/sigstore/fulcio Go	`< 1.8.3`	`1.8.3`
fulcio linuxfoundation	`< 1.8.3`	`1.8.3`

概要

Function identity.extractIssuerURL currently splits (via a call to strings.Split) its argument (which is untrusted data) on periods.

As a result, in the face of a malicious request with an (invalid) OIDC identity token in the payload containing many period characters, a call to extractIssuerURL incurs allocations to the tune of O(n) bytes (where n stands for the length of the function's argument), with a constant factor of about 16. Relevant weakness: CWE-405: Asymmetric Resource Consumption (Amplification)

Details See identity.extractIssuerURL

Impact Excessive memory allocation

NVD の説明

Fulcio is a free-to-use certificate authority for issuing code signing certificates for an OpenID Connect (OIDC) identity. Prior to 1.8.3, function identity.extractIssuerURL splits (via a call to strings.Split) its argument (which is untrusted data) on periods. As a result, in the face of a malicious request with an (invalid) OIDC identity token in the payload containing many period characters, a call to extractIssuerURL incurs allocations to the tune of O(n) bytes (where n stands for the length of the function's argument), with a constant factor of about 16. This vulnerability is fixed in 1.8.3.