{"id":"CVE-2026-76504","published":"2026-09-30T13:17:20Z","modified":"2026-10-03T00:16:39Z","title":"Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability","vendor":"Cisco","product":"Catalyst SD-WAN Manager","tier":"core","eol":null,"description":{"text":"A vulnerability in the API session-based authentication management of Cisco Catalyst SD-WAN Manager could allow an unauthenticated, remote attacker to access an affected system with privileges of the admin user.\r\n\r\nThis vulnerability is due to improper handling of URI encoding in an HTTP request, which allows the request to bypass an authentication rule that is intended to restrict access to a specific API endpoint. An attacker could exploit this vulnerability by sending a crafted HTTP request to the API of the affected system. A successful exploit could allow the attacker to bypass authentication and gain access to the API as the admin user.","provenance":"source","from":"NVD"},"summary":{"text":"A flaw in the API session-based authentication management of Cisco Catalyst SD-WAN Manager lets improper handling of URI encoding in HTTP requests bypass an authentication rule meant to restrict access to a specific API endpoint. An unauthenticated remote attacker who sends a crafted HTTP request to the affected system's API can gain access with the privileges of the admin user, requiring no credentials or user interaction.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:14:17Z"},"cvss":{"score":9.8,"severity":"CRITICAL","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.38928,"percentile":0.98587,"date":"2026-10-30","provenance":"source"},"kev":{"dateAdded":"2026-09-30","dueDate":"2026-10-03","ransomware":false,"requiredAction":"Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.","notes":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-webauth-xr8beuuU ; ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-76504","provenance":"source"},"vulncheckKev":{"dateAdded":"2026-09-30","exploitedFirstSeen":"2026-09-30","ransomware":false,"evidence":[{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-webauth-xr8beuuU","date":"2026-09-30"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2026-09-30"},{"url":"https://x.com/DefusedCyber/status/2105596103458492919","date":"2026-10-01"},{"url":"https://dashboard.shadowserver.org/statistics/honeypot/vulnerability/map/?day=2026-10-13&host_type=src&vulnerability=cve-2026-76504","date":"2026-10-13"}],"evidenceTotal":4,"provenance":"source"},"exploited":true,"otx":{"pulseCount":33,"pulses":[{"name":"Actively_Exploited_Kev | Oct 31, 2026","url":"https://otx.alienvault.com/pulse/6ae4aefab0c2191cecd41862","created":"2026-10-30"},{"name":"Actively_Exploited_Kev | Oct 30, 2026","url":"https://otx.alienvault.com/pulse/6ae35d889ea92b4ce19c2680","created":"2026-10-29"},{"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"}],"provenance":"machine"},"cwes":[{"id":"CWE-177","name":"Improper Handling of URL Encoding (Hex Encoding)"}],"references":[{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-webauth-xr8beuuU","tags":["Mitigation","Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-76504","tags":["US Government Resource"]}],"techniques":[{"id":"T1190","name":"Exploit Public-Facing Application","tactics":["initial-access"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Unauthenticated crafted HTTP request to exposed API","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"sending a crafted HTTP request to the API of the affected system","start":468,"end":532}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1078","name":"Valid Accounts","tactics":["initial-access","persistence","privilege-escalation","stealth"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Gains admin-level valid account access","mappingType":"primary_impact","evidence":[{"from":"description","quote":"gain access to the API as the admin user","start":609,"end":649}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2026-89950","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-89950","exploited":true,"exploitedSince":"2026-09-30","provenance":"source"},"exploits":[],"exploitSources":{"pocGithub":{"count":3,"skipped":0,"earliest":"2026-09-30","earliestUrl":"https://github.com/ShadowForge-Cyber/CVE-2026-76504-Proof-of-concept","repos":[{"name":"ShadowForge-Cyber/CVE-2026-76504-Proof-of-concept","url":"https://github.com/ShadowForge-Cyber/CVE-2026-76504-Proof-of-concept","stars":2,"created":"2026-09-30"},{"name":"pastelghost3/cve-2026-76504-nuclei","url":"https://github.com/pastelghost3/cve-2026-76504-nuclei","stars":0,"created":"2026-10-23"},{"name":"maxprog-svg/CVE-2026-76504-Cisco","url":"https://github.com/maxprog-svg/CVE-2026-76504-Cisco","stars":0,"created":"2026-10-23"}]},"first":{"date":"2026-09-30","source":"PoC-in-GitHub","url":"https://github.com/ShadowForge-Cyber/CVE-2026-76504-Proof-of-concept"},"provenance":"source"},"exploitRefs":[],"flow":[{"stage":"exploitation","techniques":["T1190"],"provenance":"ai"},{"stage":"primary","techniques":["T1078"],"provenance":"ai"}],"timeline":[{"date":"2026-09-30","kind":"published","label":"Published 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