{"id":"ALPINE-CVE-2026-21713","details":"A flaw in Node.js HMAC verification uses a non-constant-time comparison when validating user-provided signatures, potentially leaking timing information proportional to the number of matching bytes. Under certain threat models where high-resolution timing measurements are possible, this behavior could be exploited as a timing oracle to infer HMAC values.\r\n\r\nNode.js already provides timing-safe comparison primitives used elsewhere in the codebase, indicating this is an oversight rather than an intentional design decision.\r\n\r\nThis vulnerability affects **20.x, 22.x, 24.x, and 25.x**.","modified":"2026-04-05T16:31:37.316221Z","published":"2026-03-30T20:16:19.397Z","upstream":["CVE-2026-21713"],"references":[{"type":"ADVISORY","url":"https://security.alpinelinux.org/vuln/CVE-2026-21713"}],"affected":[{"package":{"name":"nodejs","ecosystem":"Alpine:v3.21","purl":"pkg:apk/alpine/nodejs?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"22.22.2-r0"}]}],"versions":["22.11.0-r0","22.11.0-r1","22.13.1-r0","22.15.1-r0"],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-21713.json"}},{"package":{"name":"nodejs","ecosystem":"Alpine:v3.22","purl":"pkg:apk/alpine/nodejs?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"22.22.2-r0"}]}],"versions":["22.11.0-r0","22.11.0-r1","22.11.0-r2","22.13.1-r0","22.13.1-r1","22.13.1-r2","22.13.1-r3","22.13.1-r4","22.13.1-r5","22.16.0-r0","22.16.0-r1","22.16.0-r2","22.22.0-r0"],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-21713.json"}},{"package":{"name":"nodejs","ecosystem":"Alpine:v3.23","purl":"pkg:apk/alpine/nodejs?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"24.14.1-r0"}]}],"versions":["22.11.0-r0","22.11.0-r1","22.11.0-r2","22.13.1-r0","22.13.1-r1","22.13.1-r2","22.13.1-r3","22.13.1-r4","22.13.1-r5","22.16.0-r0","22.16.0-r1","22.16.0-r2","22.16.0-r3","22.19.0-r3","22.19.0-r4","22.21.0-r0","24.11.1-r0","24.13.0-r0","24.13.0-r1"],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-21713.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"}]}