{"id":"CVE-2021-26085","kind":"vulnerability","aliases":["CVE-2021-26085"],"related":[],"title":"Atlassian Confluence Server: Atlassian Confluence Server Pre-Authorization Arbitrary File Read Vulnerability","description":"Affected versions of Atlassian Confluence Server allow remote attackers to view restricted resources via a Pre-Authorization Arbitrary File Read vulnerability in the /s/ endpoint. The affected versions are before version 7.4.10, and from version 7.5.0 before 7.12.3.","summary":"Atlassian Confluence Server has a pre-authorization arbitrary file read flaw in its /s/ endpoint, so remote attackers can view restricted files without logging in. It is listed as actively exploited in the wild and tagged as used in ransomware campaigns.","severity":"high","cvss":5.3,"epss":0.99937,"exploited":true,"exploited_at":"2022-03-28T00:00:00+00:00","products":[{"name":"Atlassian Confluence Server","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["atlassian","confluence","exploited","package","ransomware","self-hosted"],"not_affected_if":["atlassian-cloud","managed-hosting"],"how_to_check":null,"fix":"Apply the Atlassian vendor update for Confluence Server per vendor instructions; the sources do not name the fixed version.","status":"open","published_at":"2021-08-03T00:15:08+00:00","first_seen_at":"2026-10-23T19:11:52+00:00","triaged_at":"2026-10-23T21:19:49+00:00","updated_at":"2026-10-23T21:57:35+00:00","category":"package","confidence":0.8,"triage":{"at":"2026-10-23T21:19:49Z","model":"claude-haiku-5-5","output":{"fix":"Apply the Atlassian vendor update for Confluence Server per vendor instructions; the sources do not name the fixed version.","reach":"internet","impact":"high","summary":"Atlassian Confluence Server has a pre-authorization arbitrary file read flaw in its /s/ endpoint, so remote attackers can view restricted files without logging in. It is listed as actively exploited in the wild and tagged as used in ransomware campaigns.","category":"package","who_cares":["confluence","self-hosted","atlassian"],"confidence":0.8,"needs_auth":"no","worst_case":"Attacker reads server files, including configuration and credentials, without authentication","analyst_note":"Find the fixed Confluence Server versions and a detection method (log or path check) in the Atlassian advisory for CVE-2021-26085; the sources give neither.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["managed-hosting","atlassian-cloud"],"user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000472,"input_tokens":2863,"output_tokens":371,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2021':15A,18A '-26085':16A,19A '/s':45B,97C '7.12.3':111C '7.4.10':105C '7.5.0':109C 'activ':61B 'affect':73C,100C 'allow':79C 'arbitrari':10A,39B,91C 'atlassian':1A,4A,20A,23B,31B,76C 'attack':49B,81C 'author':9A,38B,90C 'campaign':72B 'confluenc':2A,5A,24B,32B,77C 'confluence':21A 'cve':14A,17A 'endpoint':46B,98C 'exploit':25B,62B 'file':11A,40B,53B,92C 'flaw':42B 'host':30B 'list':59B 'log':55B 'packag':26B 'pre':8A,37B,89C 'pre-author':7A,36B,88C 'ransomwar':27B,71B 'read':12A,41B,93C 'remot':48B,80C 'resourc':85C 'restrict':52B,84C 'self':29B 'self-host':28B 'server':3A,6A,22A,33B,78C 'tag':67B 'use':69B 'version':74C,101C,104C,108C 'via':86C 'view':51B,83C 'vulner':13A,94C 'wild':65B 'without':54B","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2021-08-03T00:15:08+00:00","kev":{"dateAdded":"2022-03-28","dueDate":"2022-04-18","requiredAction":"Apply updates per vendor instructions.","knownRansomwareCampaignUse":"Known"},"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","cvss_by":"nvd@nist.gov","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2021-26085","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2021-26085","severity":null,"published_at":"2022-03-28T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:52+00:00","fetched_at":"2026-10-25T12:39:24+00:00","note":null},{"source":"epss","external_id":"CVE-2021-26085","url":"https://api.first.org/data/v1/epss?cve=CVE-2021-26085","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-23T19:13:44+00:00","fetched_at":"2026-10-23T19:13:44+00:00","note":null},{"source":"nvd","external_id":"CVE-2021-26085","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-26085","severity":null,"published_at":"2021-08-03T00:15:08+00:00","modified_at":"2026-06-17T03:42:49+00:00","first_seen_at":"2026-10-23T21:57:35+00:00","fetched_at":"2026-10-23T21:57:35+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"}