{"id":"CVE-2025-35939","kind":"vulnerability","aliases":["CVE-2025-35939"],"related":[],"title":"craftcms craft cms: Craft CMS stores arbitrary content provided by unauthenticated users in session files","description":"Craft CMS stores arbitrary content provided by unauthenticated users in session files. This content could be accessed and executed, possibly using an independent vulnerability. Craft CMS redirects requests that require authentication to the login page and generates a session file on the server at '/var/lib/php/sessions'. Such session files are named 'sess_[session_value]', where '[session_value]' is provided to the client in a 'Set-Cookie' response header. Craft CMS stores the return URL requested by the client without sanitizing parameters. Consequently, an unauthenticated client can introduce arbitrary values, such as PHP code, to a known local file location on the server. Craft CMS versions 5.7.5 and 4.15.3 have been released to address this issue.","summary":"Craft CMS, a PHP content management system, lets an unauthenticated client write attacker-chosen values such as PHP code into a known local file on the server. An attacker can run code on the server, and the CVE notes it can be chained with CVE-2024-58136 (exploited as CVE-2025-32432).","severity":"critical","cvss":6.9,"epss":null,"exploited":true,"exploited_at":"2025-06-02T00:00:00+00:00","products":[{"name":"Craft CMS Craft CMS","fixed":[],"affected":"","ecosystem":"vendor"},{"name":"craftcms craft cms","fixed":["4.15.3"],"affected":"< 4.15.3","ecosystem":"vendor"},{"name":"craftcms craft cms","fixed":["5.7.5"],"affected":">= 5.0.0, < 5.7.5","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["craft-cms","exploited","package","php","self-hosted"],"not_affected_if":["not-craft-cms"],"how_to_check":null,"fix":"Apply the vendor mitigations per Craft CMS instructions; the sources do not name a fixed version.\nIf no mitigation exists, CISA says to discontinue use of the product.","status":"open","published_at":"2025-05-07T23:15:54+00:00","first_seen_at":"2026-10-23T19:11:51+00:00","triaged_at":"2026-10-23T20:48:27+00:00","updated_at":"2026-10-23T22:29:05+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-10-23T20:48:27Z","model":"claude-haiku-5-5","output":{"fix":"Apply the vendor mitigations per Craft CMS instructions; the sources do not name a fixed version.\nIf no mitigation exists, CISA says to discontinue use of the product.","reach":"internet","summary":"Craft CMS, a PHP content management system, lets an unauthenticated client write attacker-chosen values such as PHP code into a known local file on the server. An attacker can run code on the server, and the CVE notes it can be chained with CVE-2024-58136 (exploited as CVE-2025-32432).","category":"package","who_cares":["craft-cms","php","self-hosted"],"confidence":0.6,"needs_auth":"no","worst_case":"Attacker runs arbitrary PHP code on the server, reading secrets and taking over the site.","analyst_note":"Find the affected and fixed Craft CMS versions and vendor mitigation steps from the Craft CMS security advisory; check CVE-2024-58136 and CVE-2025-32432 for the chained exploit details.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["not-craft-cms"],"user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"critical"},"cost_usd":0.000468,"input_tokens":2603,"output_tokens":415,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2024':87B '-2025':17A,20A,92B '-32432':93B '-35939':18A,21A '-58136':88B '/var/lib/php/sessions':138C '4.15.3':201C '5.7.5':199C 'access':110C 'address':206C 'arbitrari':7A,97C,181C 'attack':54B,70B 'attacker-chosen':53B 'authent':124C 'chain':84B 'chosen':55B 'client':51B,154C,171C,178C 'cms':3A,5A,23A,25A,28A,31A,34B,42B,95C,119C,163C,197C 'code':60B,73B,186C 'consequ':175C 'content':8A,45B,98C,107C 'cooki':159C 'could':108C 'craft':2A,4A,22A,24A,27A,30A,33B,41B,94C,118C,162C,196C 'craft-cm':32B 'craftcm':1A 'craftcms':26A,29A 'cve':16A,19A,79B,86B,91B 'execut':112C 'exploit':35B,89B 'file':15A,65B,105C,133C,141C,191C 'generat':130C 'header':161C 'host':40B 'independ':116C 'introduc':180C 'issu':208C 'known':63B,189C 'let':48B 'local':64B,190C 'locat':192C 'login':127C 'manag':46B 'name':143C 'note':80B 'packag':36B 'page':128C 'paramet':174C 'php':37B,44B,59B,185C 'possibl':113C 'provid':9A,99C,151C 'redirect':120C 'releas':204C 'request':121C,168C 'requir':123C 'respons':160C 'return':166C 'run':72B 'sanit':173C 'self':39B 'self-host':38B 'server':68B,76B,136C,195C 'sess':144C 'session':14A,104C,132C,140C,145C,148C 'set':158C 'set-cooki':157C 'store':6A,96C,164C 'system':47B 'unauthent':11A,50B,101C,177C 'url':167C 'use':114C 'user':12A,102C 'valu':56B,146C,149C,182C 'version':198C 'vulner':117C 'without':172C 'write':52B","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2025-05-07T23:15:54+00:00","kev":{"dateAdded":"2025-06-02","dueDate":"2025-06-23","requiredAction":"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/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","cvss_by":"9119a7d8-5eab-497f-8521-727c672e3725","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2025-35939","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2025-35939","severity":null,"published_at":"2025-06-02T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:51+00:00","fetched_at":"2026-10-25T19:35:20+00:00","note":null},{"source":"nvd","external_id":"CVE-2025-35939","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-35939","severity":null,"published_at":"2025-05-07T23:15:54+00:00","modified_at":"2026-06-17T09:14:18+00:00","first_seen_at":"2026-10-23T22:29:05+00:00","fetched_at":"2026-10-23T22:29:05+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}