{"id":"CVE-2026-108082","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-108082","generatedAt":"2026-10-28T10:47:50.952Z","title":"Symfony is a PHP framework for web and console applications and a set of reusable PHP components.","description":"Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to versions 5.4.54, 6.4.46, 7.4.19, and 8.1.7, HeaderUtils::split() parsed header values with a pattern whose token alternative also matched whitespace, followed by a (?<!\\s) lookbehind. A run of whitespace placed before a separator could be divided among the iterations of the enclosing repetition in exponentially many ways, and the engine tried all of them before settling. HeaderBag calls it for the Cache-Control header whenever a Request is built, so any application handling HTTP requests is reachable, with no authentication.\n\n\n\nA single request carrying such a header costs close to a second of CPU (813 ms for a run of 17 spaces in an 8 KB header on PHP 8.5, doubling with each extra space). From 18 spaces on, preg_match_all() gives up at pcre.backtrack_limit and split() returns an empty array, so every directive of the header is silently dropped.\n\n\n\nThis issue affects symfony/http-foundation v4.1.0-BETA1 through v5.4.53, v6.0.0-BETA1 through v6.4.45, v7.0.0-BETA1 through v7.4.18, and v8.0.0-BETA1 through v8.1.6.","published":"2026-10-15T15:17:23.000Z","lastModified":"2026-10-16T16:00:34.000Z","status":"Awaiting Analysis","sourceIdentifier":"596c5446-0ce5-4ba2-aa66-48b3b757a647","cvss":{"version":"4.0","score":8.7,"severity":"HIGH","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-1333"],"affected":[],"epss":{"score":0.0048,"percentile":0.41239,"date":"2026-10-27","history":[{"date":"2026-10-16","score":0.00367,"percentile":0.28963}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.48%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-15T15:17:23.000Z","detail":{"score":"8.7","severity":"HIGH","publishedAt":"2026-10-15T15:17:22.583Z"},"summary":"New CVE, high severity (CVSS 8.7)."}],"references":[{"url":"https://github.com/symfony/symfony/pull/66048","source":"596c5446-0ce5-4ba2-aa66-48b3b757a647"},{"url":"https://github.com/symfony/symfony/pull/66491","source":"596c5446-0ce5-4ba2-aa66-48b3b757a647"},{"url":"https://github.com/symfony/symfony/security/advisories/GHSA-r925-mgvr-h9cc","source":"596c5446-0ce5-4ba2-aa66-48b3b757a647"},{"url":"https://symfony.com/blog/cve-2026-108082-redos-in-headerutils-split-reachable-through-the-cache-control-request-header","source":"596c5446-0ce5-4ba2-aa66-48b3b757a647"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-108082","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}