{"schemaVersion":3,"id":"CVE-2026-108082","aliases":["UBUNTU-CVE-2026-108082","DEBIAN-CVE-2026-108082"],"status":"published","duplicateOf":null,"title":null,"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.","dates":{"published":"2026-10-15T14:46:01.594Z","modified":"2026-10-15T18:04:45.913Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":8.7,"severity":"high","version":"4.0","versionLabel":"v4.0","source":"CVE.org","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","computed":false,"selection":"backend-summary"},"metrics":[{"version":"4.0","versionLabel":"v4.0","source":"CVE.org","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","exploitability":null,"impact":null,"computed":false},{"version":"4.0","versionLabel":"v4.0","source":"NVD","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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","exploitability":null,"impact":null,"computed":false},{"version":"4.0","versionLabel":"v4.0","source":"OSV · Ubuntu","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","exploitability":null,"impact":null,"computed":true},{"version":"4.0","versionLabel":"v4.0","source":"OSV · Debian","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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","exploitability":null,"impact":null,"computed":true}]},"epss":{"probability":0.00367,"percentile":0.29057,"severity":"low","asOf":"2026-10-19T00:00:00.000Z","change":{"pp":null,"baselineDate":null,"baselineScore":null},"history":[{"date":"2026-10-16T00:00:00.000Z","score":0.00367,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00367,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00367,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00367,"percentile":0.29057}],"last30":[{"date":"2026-10-16T00:00:00.000Z","score":0.00367,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00367,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00367,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00367,"percentile":0.29057}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[{"id":"CWE-1333","name":"Inefficient Regular Expression Complexity","description":"The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.","type":"weakness","status":"Draft","abstraction":"Base","likelihoodOfExploit":"High","url":"https://cwe.mitre.org/data/definitions/1333.html"}],"affected":[{"vendor":"debian","product":"symfony","name":"symfony","label":"symfony","ecosystem":"Debian","cpePart":null,"purl":"pkg:deb/debian/symfony","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null},{"text":"< 7.4.19+dfsg-1","noFixRecorded":false,"fixedIn":null}],"versionsText":"All versions (No fix recorded) | < 7.4.19+dfsg-1","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"symfony","name":"symfony","label":"symfony","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/symfony","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"sensiolabs","product":"symfony","name":"symfony","label":"symfony","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≥ v4.1.0-BETA1, < v5.4.54","noFixRecorded":false,"fixedIn":null},{"text":"≥ v6.0.0-BETA1, < v6.4.46","noFixRecorded":false,"fixedIn":null},{"text":"≥ v7.0.0-BETA1, < v7.4.19","noFixRecorded":false,"fixedIn":null},{"text":"≥ v8.0.0-BETA1, < v8.1.7","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ v4.1.0-BETA1, < v5.4.54 | ≥ v6.0.0-BETA1, < v6.4.46 | ≥ v7.0.0-BETA1, < v7.4.19 | ≥ v8.0.0-BETA1, < v8.1.7","eol":{"isEol":null,"eolDate":null,"matchMethod":"cpe","cycle":null,"product":{"name":"symfony","label":"Symfony","category":"framework"}},"hubHref":"/vendor/sensiolabs/symfony"}],"affectedCount":3,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://github.com/symfony/symfony/pull/66048","label":"github.com/symfony/symfony/pull/66048","hostname":"github.com","tags":["Patch","REPORT"]},{"url":"https://github.com/symfony/symfony/pull/66491","label":"github.com/symfony/symfony/pull/66491","hostname":"github.com","tags":["Patch","REPORT"]},{"url":"https://github.com/symfony/symfony/security/advisories/GHSA-r925-mgvr-h9cc","label":"github.com/symfony/symfony/security/advisories/GHSA-r925-mgvr-h9cc","hostname":"github.com","tags":["Vendor Advisory","REPORT"]},{"url":"https://symfony.com/blog/cve-2026-108082-redos-in-headerutils-split-reachable-through-the-cache-control-request-header","label":"symfony.com/blog/…","hostname":"symfony.com","tags":["Vendor Advisory","REPORT"]},{"url":"https://ubuntu.com/security/CVE-2026-108082","label":"ubuntu.com/security/CVE-2026-108082","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-108082","label":"www.cve.org/CVERecord?id=CVE-2026-108082","hostname":"www.cve.org","tags":["REPORT"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-108082","label":"security-tracker.debian.org/tracker/CVE-2026-108082","hostname":"security-tracker.debian.org","tags":["Advisory"]}],"lineage":{"upstream":[],"downstream":[],"duplicates":[],"related":[]},"timeline":[{"kind":"published","date":"2026-10-15T14:46:01.594Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-10-15T18:04:45.913Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":35,"level":"medium","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-20T03:09:56.486Z","stale":false,"partial":false}}