{"id":"CVE-2026-20004","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-20004","generatedAt":"2026-10-28T03:22:58.032Z","title":"A vulnerability in the TLS library of Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to exhaust the available memory of an affected device.","description":"A vulnerability in the TLS library of Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to exhaust the available memory of an affected device.\r\n\r This vulnerability is due to improper management of memory resources during TLS connection setup. An attacker could exploit this vulnerability by repeatedly triggering the conditions that cause the memory increase. This could be done in a variety of ways, such as by repeatedly attempting Extensible Authentication Protocol (EAP) authentication when local EAP is enabled on an affected device or by using a machine-in-the-middle attack and resetting TLS connections between the affected device and other devices. A successful exploit could allow the attacker to exhaust the available memory on an affected device, resulting in an unexpected reload and a denial of service (DoS) condition.","published":"2026-03-25T16:16:11.000Z","lastModified":"2026-09-28T15:18:43.000Z","status":"Analyzed","sourceIdentifier":"psirt@cisco.com","cvss":{"version":"3.1","score":7.4,"severity":"HIGH","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H"},"cwe":["CWE-771"],"affected":["cisco/ios xe"],"epss":{"score":0.00187,"percentile":0.08246,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.19%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-tls-dos-TVgLDEZL","tags":["Vendor Advisory"],"source":"psirt@cisco.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-20004","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}