{"id":"CVE-2021-26086","kind":"vulnerability","aliases":["CVE-2021-26086"],"related":[],"title":"Affected versions of Atlassian Jira Server and Data Center allow remote attackers to read particular files via a…","description":"Affected versions of Atlassian Jira Server and Data Center allow remote attackers to read particular files via a path traversal vulnerability in the /WEB-INF/web.xml endpoint. The affected versions are before version 8.5.14, from version 8.6.0 before 8.13.6, and from version 8.14.0 before 8.16.1.","summary":"Atlassian Jira Server and Data Center has a path traversal flaw that lets a remote attacker read files through the /WEB-INF/web.xml endpoint. Attackers are exploiting it in the wild, according to CISA's Known Exploited Vulnerabilities catalog.","severity":"high","cvss":5.3,"epss":null,"exploited":true,"exploited_at":"2024-11-12T00:00:00+00:00","products":[{"name":"Atlassian Jira Server and Data Center","fixed":[],"affected":"","ecosystem":"vendor"},{"name":"atlassian jira data center","fixed":["8.5.14"],"affected":"< 8.5.14","ecosystem":"vendor"},{"name":"atlassian jira data center","fixed":["8.13.6"],"affected":">= 8.6.0, < 8.13.6","ecosystem":"vendor"},{"name":"atlassian jira data center","fixed":["8.16.1"],"affected":">= 8.14.0, < 8.16.1","ecosystem":"vendor"},{"name":"atlassian jira server","fixed":["8.5.14"],"affected":"< 8.5.14","ecosystem":"vendor"},{"name":"atlassian jira server","fixed":["8.13.6"],"affected":">= 8.6.0, < 8.13.6","ecosystem":"vendor"},{"name":"atlassian jira server","fixed":["8.16.1"],"affected":">= 8.14.0, < 8.16.1","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["exploited","jira","jira-data-center","jira-server","self-hosted","vendor"],"not_affected_if":["atlassian-cloud"],"how_to_check":null,"fix":"Apply the mitigation from Atlassian's vendor advisory for CVE-2021-26086, or stop using the product if no mitigation is available (per CISA required action).","status":"open","published_at":"2021-08-16T01:15:06+00:00","first_seen_at":"2026-10-23T19:11:51+00:00","triaged_at":"2026-10-23T20:56:15+00:00","updated_at":"2026-10-23T22:29:05+00:00","category":"vendor","confidence":0.6,"triage":{"at":"2026-10-23T20:56:15Z","model":"claude-haiku-5-5","output":{"fix":"Apply the mitigation from Atlassian's vendor advisory for CVE-2021-26086, or stop using the product if no mitigation is available (per CISA required action).\nunknown","reach":"internet","impact":"medium","summary":"Atlassian Jira Server and Data Center has a path traversal flaw that lets a remote attacker read files through the /WEB-INF/web.xml endpoint. Attackers are exploiting it in the wild, according to CISA's Known Exploited Vulnerabilities catalog.","category":"vendor","who_cares":["jira","jira-server","jira-data-center","self-hosted"],"confidence":0.6,"needs_auth":"unknown","worst_case":"Remote attacker reads server files, possibly including configuration and secrets","analyst_note":"Find the Atlassian advisory for CVE-2021-26086 and confirm affected and fixed versions, the exact mitigation, and what files are readable without auth.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["atlassian-cloud"],"user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000484,"input_tokens":2838,"output_tokens":400,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2021':19A,22A '-26086':20A,23A '/web-inf/web.xml':84B,124C '8.13.6':137C '8.14.0':141C '8.16.1':143C '8.5.14':132C '8.6.0':135C 'accord':93B 'affect':1A,101C,127C 'allow':10A,110C 'and':27A 'atlassian':4A,24A,30A,34A,38A,42A,45A,48A,64B,104C 'attack':12A,79B,86B,112C 'catalog':100B 'center':9A,29A,33A,37A,41A,56B,69B,109C 'cisa':95B 'cve':18A,21A 'data':8A,28A,32A,36A,40A,55B,68B,108C 'endpoint':85B,125C 'exploit':51B,88B,98B 'file':16A,81B,116C 'flaw':74B 'host':62B 'jira':5A,25A,31A,35A,39A,43A,46A,49A,52B,54B,58B,65B,105C 'jira-data-cent':53B 'jira-serv':57B 'known':97B 'let':76B 'particular':15A,115C 'path':72B,119C 'read':14A,80B,114C 'remot':11A,78B,111C 'self':61B 'self-host':60B 'server':6A,26A,44A,47A,50A,59B,66B,106C 'travers':73B,120C 'vendor':63B 'version':2A,102C,128C,131C,134C,140C 'via':17A,117C 'vulner':99B,121C 'wild':92B","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2021-08-16T01:15:06+00:00","kev":{"dateAdded":"2024-11-12","dueDate":"2024-12-03","requiredAction":"Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.","knownRansomwareCampaignUse":"Unknown"},"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-2021-26086","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2021-26086","severity":null,"published_at":"2024-11-12T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:51+00:00","fetched_at":"2026-10-25T11:39:15+00:00","note":null},{"source":"nvd","external_id":"CVE-2021-26086","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-26086","severity":null,"published_at":"2021-08-16T01:15:06+00:00","modified_at":"2026-06-17T03:42:50+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"}