{"id":"CVE-2015-6835","url":"https://www.cyber-defence.io/tools/cve/CVE-2015-6835","generatedAt":"2026-11-05T05:27:56.280Z","title":"The session deserializer in PHP before 5.4.45, 5.5.x before 5.5.29, and 5.6.x before 5.6.13 mishandles multiple php_var_unserialize calls, which allow remote attackers to execute arbitrary code or cause a denial of service (use-after-free) via crafted…","description":"The session deserializer in PHP before 5.4.45, 5.5.x before 5.5.29, and 5.6.x before 5.6.13 mishandles multiple php_var_unserialize calls, which allow remote attackers to execute arbitrary code or cause a denial of service (use-after-free) via crafted session content.","published":"2016-05-16T10:59:20.000Z","lastModified":"2026-06-17T00:31:30.000Z","status":"Modified","sourceIdentifier":"security@opentext.com","cvss":{"version":"3.0","score":9.8,"severity":"CRITICAL","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":[],"affected":["php/php"],"epss":{"score":0.36163,"percentile":0.98481,"date":"2026-11-04","history":[{"date":"2026-09-21","score":0.31903,"percentile":0.98268},{"date":"2026-09-22","score":0.36992,"percentile":0.98445}]},"kev":{"listed":false},"exploits":{"count":1,"verified":true,"firstPublished":"2015-09-09","source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[{"edbId":38123,"kind":"exploit","title":"PHP Session Deserializer - Use-After-Free","url":"https://www.exploit-db.com/exploits/38123","sourceUrl":"https://gitlab.com/exploit-database/exploitdb/-/blob/main/exploits/php/dos/38123.txt","file":"exploits/php/dos/38123.txt","published":"2015-09-09","added":"2015-09-09","updated":"2015-09-09","author":"Taoguang Chen","type":"dos","platform":"php","port":null,"verified":true,"codes":["CVE-2015-6835","OSVDB-126962"],"tags":null,"aliases":null,"applicationUrl":null,"screenshotUrl":null,"referenceUrl":null}]},"verdict":{"level":"urgent","text":"EPSS puts the probability of exploitation in the next 30 days at 36.2%, higher than 98% of all known CVEs. Patch or mitigate before the next change window."},"changes":[{"kind":"epss","label":"EPSS jump","at":"2026-09-22T00:00:00.000Z","detail":{"to":0.36992,"from":0.31903,"percentile":0.98445},"summary":"EPSS moved from 31.9% to 37.0% probability of exploitation in the next thirty days."}],"references":[{"url":"http://php.net/ChangeLog-5.php","source":"security@opentext.com"},{"url":"http://www.debian.org/security/2015/dsa-3358","source":"security@opentext.com"},{"url":"http://www.securityfocus.com/bid/76734","source":"security@opentext.com"},{"url":"http://www.securitytracker.com/id/1033548","source":"security@opentext.com"},{"url":"https://bugs.php.net/bug.php?id=70219","source":"security@opentext.com"},{"url":"https://security.gentoo.org/glsa/201606-10","source":"security@opentext.com"},{"url":"http://php.net/ChangeLog-5.php","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.debian.org/security/2015/dsa-3358","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.securityfocus.com/bid/76734","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.securitytracker.com/id/1033548","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://bugs.php.net/bug.php?id=70219","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.gentoo.org/glsa/201606-10","source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2015-6835","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."}