{"id":"UBUNTU-CVE-2025-66506","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.","modified":"2026-05-20T16:11:28.181857900Z","published":"2025-12-04T22:15:00Z","upstream":["CVE-2025-66506"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2025-66506"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2025-66506"},{"type":"REPORT","url":"https://github.com/sigstore/fulcio/commit/765a0e57608b9ef390e1eeeea8595b9054c63a5a"},{"type":"REPORT","url":"https://github.com/sigstore/fulcio/security/advisories/GHSA-f83f-xpx7-ffpw"}],"affected":[{"package":{"name":"golang-github-sigstore-fulcio","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/golang-github-sigstore-fulcio?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.6.5-1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.6.5-1","binary_name":"golang-github-sigstore-fulcio-dev"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-66506.json"}},{"package":{"name":"golang-github-sigstore-fulcio","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/golang-github-sigstore-fulcio?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.6.5-1","1.7.1-1"],"ecosystem_specific":{"binaries":[{"binary_name":"golang-github-sigstore-fulcio-dev","binary_version":"1.7.1-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-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"},{"type":"Ubuntu","score":"medium"}]}