{"id":"CVE-2025-66506","summary":"Fulcio allocates excessive memory during token parsing","details":"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.","aliases":["GHSA-f83f-xpx7-ffpw","GO-2025-4193"],"modified":"2026-04-02T13:02:38.204388Z","published":"2025-12-04T22:04:41.637Z","related":["CGA-63x2-wrq7-39v8","SUSE-SU-2025:4395-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/66xxx/CVE-2025-66506.json","cwe_ids":["CWE-405"],"cna_assigner":"GitHub_M"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/66xxx/CVE-2025-66506.json"},{"type":"ADVISORY","url":"https://github.com/sigstore/fulcio/security/advisories/GHSA-f83f-xpx7-ffpw"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-66506"},{"type":"FIX","url":"https://github.com/sigstore/fulcio/commit/765a0e57608b9ef390e1eeeea8595b9054c63a5a"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/sigstore/fulcio","events":[{"introduced":"0"},{"fixed":"3622f6e62cf74ff1477422a8c3aad4ca338ed047"}]}],"versions":["0.1.0","v0.1.1","v0.2.0","v0.3.0","v0.4.0","v0.4.1","v0.5.0","v0.5.1","v0.5.2","v0.5.3","v0.5.4","v0.6.0","v1.0.0","v1.0.0-rc.0","v1.1.0","v1.2.0","v1.3.0","v1.3.1","v1.3.2","v1.3.3","v1.3.4","v1.4.0","v1.4.1","v1.4.2","v1.4.3","v1.4.4","v1.4.5","v1.5.0","v1.5.1","v1.6.0","v1.6.1","v1.6.2","v1.6.3","v1.6.4","v1.6.5","v1.6.6","v1.7.0","v1.7.1","v1.8.0","v1.8.1","v1.8.2"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-66506.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}