{"id":"CVE-2019-18887","aliases":["GHSA-q8hg-pf8v-cxrv"],"url":"https://o3.security/vulnerability/CVE-2019-18887","summary":"Symfony Http-Kernel has non-constant time comparison in UriSigner","details":"When checking the signature of an URI (an ESI fragment URL for instance), the URISigner did not used a constant time string comparison function, resulting in a potential remote timing attack vulnerability.","published":"2019-11-21T23:15:13.403Z","modified":"2026-10-24T10:50:35.298279677Z","cvss":{"score":8.1,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":{"score":0.01338,"percentile":0.6988,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Packagist","name":"symfony/http-kernel","fixedVersion":"2.8.52"},{"ecosystem":"Packagist","name":"symfony/http-kernel","fixedVersion":"3.4.35"},{"ecosystem":"Packagist","name":"symfony/http-kernel","fixedVersion":"4.2.12"},{"ecosystem":"Packagist","name":"symfony/http-kernel","fixedVersion":"4.3.8"},{"ecosystem":"Packagist","name":"symfony/symfony","fixedVersion":"2.8.52"},{"ecosystem":"Packagist","name":"symfony/symfony","fixedVersion":"3.4.35"},{"ecosystem":"Packagist","name":"symfony/symfony","fixedVersion":"4.2.12"},{"ecosystem":"Packagist","name":"symfony/symfony","fixedVersion":"4.3.8"}],"fix":null,"references":[{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DZNXRVHDQBNZQUCNRVZICPPBFRAUWUJX/"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UED22BOXTL2SSFMGYKA64ZFHGLLJG3EA/"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VXEAOEANNIVYANTMOJ42NKSU6BGNBULZ/"},{"type":"ADVISORY","url":"https://github.com/symfony/symfony/releases/tag/v4.3.8"},{"type":"ADVISORY","url":"https://symfony.com/blog/cve-2019-18887-use-constant-time-comparison-in-urisigner"},{"type":"ADVISORY","url":"https://symfony.com/blog/symfony-4-3-8-released"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2019-18887"},{"type":"WEB","url":"https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/http-kernel/CVE-2019-18887.yaml"},{"type":"WEB","url":"https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2019-18887.yaml"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DZNXRVHDQBNZQUCNRVZICPPBFRAUWUJX"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UED22BOXTL2SSFMGYKA64ZFHGLLJG3EA"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VXEAOEANNIVYANTMOJ42NKSU6BGNBULZ"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DZNXRVHDQBNZQUCNRVZICPPBFRAUWUJX"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UED22BOXTL2SSFMGYKA64ZFHGLLJG3EA"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VXEAOEANNIVYANTMOJ42NKSU6BGNBULZ"},{"type":"WEB","url":"https://symfony.com/cve-2019-18887"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-24T10:50:35.298279677Z"}}