{"id":"CVE-2021-26085","published":"2021-08-03T00:15:08Z","modified":"2026-06-17T03:42:49Z","title":"Atlassian Confluence Server Pre-Authorization Arbitrary File Read Vulnerability","vendor":"Atlassian","product":"Confluence Server","tier":"core","eol":null,"description":{"text":"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.","provenance":"source","from":"NVD"},"summary":{"text":"The Atlassian Confluence Server product has a pre-authorization arbitrary file read flaw in its /s/ endpoint, which allows remote attackers to view restricted resources. An attacker needs only network access to the server; no authentication, user interaction, or specific configuration is required.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-29T08:31:40Z"},"cvss":{"score":5.3,"severity":"MEDIUM","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","provenance":"source","from":"NVD"},"epss":{"score":0.99937,"percentile":0.99971,"date":"2026-10-29","provenance":"source"},"kev":{"dateAdded":"2022-03-28","dueDate":"2022-04-18","ransomware":true,"requiredAction":"Apply updates per vendor instructions.","notes":"https://nvd.nist.gov/vuln/detail/CVE-2021-26085","provenance":"source"},"vulncheckKev":{"dateAdded":"2022-03-28","exploitedFirstSeen":"2022-03-28","ransomware":true,"evidence":[{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2022-03-28"},{"url":"https://static.tenable.com/marketing/whitepapers/Whitepaper-Ransomware_Ecosystem.pdf","date":"2022-06-22"},{"url":"https://www.csoonline.com/article/2096402/most-attacks-affecting-smbs-target-five-older-vulnerabilities.html","date":"2024-04-30"},{"url":"https://go.catonetworks.com/rs/245-RJK-441/images/CATO-NETWORKS-THREAT-REPORT2024.pdf","date":"2024-05-07"},{"url":"https://www.sonicwall.com/medialibrary/en/white-paper/mid-year-2024-cyber-threat-report.pdf","date":"2024-07-23"},{"url":"https://go.catonetworks.com/rs/245-RJK-441/images/CATO_CTRL_Report_Q3_2024.pdf","date":"2024-11-20"},{"url":"https://fortiguard.fortinet.com/outbreak-alert/iran-linked-cyber-attacks","date":"2026-03-31"}],"evidenceTotal":7,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"},{"name":"Actively_Exploited_Kev | Oct 18, 2026","url":"https://otx.alienvault.com/pulse/6ad38c22e1848f8189d1c121","created":"2026-10-17"}],"provenance":"machine"},"cwes":[{"id":"CWE-425","name":"Direct Request"}],"references":[{"url":"http://packetstormsecurity.com/files/164401/Atlassian-Confluence-Server-7.5.1-Arbitrary-File-Read.html","tags":["Exploit","Third Party Advisory","VDB Entry"]},{"url":"https://jira.atlassian.com/browse/CONFSERVER-67893","tags":["Issue Tracking","Vendor Advisory"]},{"url":"http://packetstormsecurity.com/files/164401/Atlassian-Confluence-Server-7.5.1-Arbitrary-File-Read.html","tags":["Exploit","Third Party Advisory","VDB Entry"]},{"url":"https://jira.atlassian.com/browse/CONFSERVER-67893","tags":["Issue Tracking","Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26085","tags":["US Government Resource"]}],"techniques":[{"id":"T1190","name":"Exploit Public-Facing Application","tactics":["initial-access"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Improper Access Control","mappingType":"exploitation_technique","evidence":[],"comment":"This vulnerability allows viewing of restricted resources via a pre-authorization arbitrary file read vulnerability.","confidence":"high"},{"id":"T1005","name":"Data from Local System","tactics":["collection"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Improper Access Control","mappingType":"primary_impact","evidence":[],"comment":"This vulnerability allows viewing of restricted resources via a pre-authorization arbitrary file read vulnerability.","confidence":"high"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2021-12906","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-12906","exploited":true,"exploitedSince":"2022-03-28","provenance":"source"},"exploits":[{"id":50377,"url":"https://www.exploit-db.com/exploits/50377","title":"Atlassian Confluence 7.12.2 - Pre-Authorization Arbitrary File Read","type":"webapps","platform":"java","date":"2021-10-05","verified":false,"provenance":"source"}],"exploitSources":{"exploitdb":{"count":1,"earliest":"2021-10-05"},"pocGithub":{"count":1,"skipped":0,"earliest":"2021-10-05","earliestUrl":"https://github.com/ColdFusionX/CVE-2021-26085","repos":[{"name":"ColdFusionX/CVE-2021-26085","url":"https://github.com/ColdFusionX/CVE-2021-26085","stars":13,"created":"2021-10-05"}]},"nuclei":[{"id":"CVE-2021-26085","name":"Atlassian Confluence Server - Local File Inclusion","severity":"medium","path":"http/cves/2021/CVE-2021-26085.yaml","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-26085.yaml"}],"first":{"date":"2021-10-05","source":"Exploit-DB","url":"https://www.exploit-db.com/exploits/50377"},"provenance":"source"},"exploitRefs":["http://packetstormsecurity.com/files/164401/Atlassian-Confluence-Server-7.5.1-Arbitrary-File-Read.html"],"flow":[{"stage":"exploitation","techniques":["T1190"],"provenance":"source"},{"stage":"primary","techniques":["T1005"],"provenance":"source"}],"timeline":[{"date":"2021-08-03","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-26085","provenance":"source"},{"date":"2021-10-05","kind":"exploit-public","label":"First public exploit: Exploit-DB (EDB-50377); 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1 Exploit-DB entry; 1 PoC-in-GitHub repo; 1 nuclei template"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":3.71,"detail":"base score 5.3"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}