Vulnerability details

CVE-2026-20004

Cisco IOS XE Software
CVSS 3.1
7.4High

Official 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. 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.

CVSS scores

ScoreVersionSourceVector
7.4High 3.1 CVEProject cvelistV5 (CNA) (cisco) CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Affected products

VendorProductVersionsSource
Cisco Cisco IOS XE Software 16.10.1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.10.1a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.10.1b CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.10.1c CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.10.1d CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.10.1e CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.10.1f CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.10.1g CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.10.1s CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.10.2 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.10.3 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.11.1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.11.1a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.11.1b CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.11.1s CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.11.2 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.10 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.10a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.11 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.12 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.13 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.14 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.15 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.1a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.1c CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.1s CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.1t CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.1w CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.1x CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.1y CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.1z1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.1z2 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.2 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.2a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.2s CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.3 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.3a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.3s CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.4 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.4a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.5 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.5a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.5b CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.6 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.6a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.7 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.8 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.12.9 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.9.1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.9.1a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.9.1b CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.9.1s CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.9.2 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.9.3 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.9.3a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.9.4 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.9.5 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.9.5f CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.9.6 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.9.7 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 16.9.8 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.1.1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.1.1a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.1.1s CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.1.1t CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.1.3 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.10.1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.10.1a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.10.1b CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.11.1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.11.1a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.12.1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.12.1a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.12.1w CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.12.1x CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.12.1y CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.12.1z CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.12.1z1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.12.1z2 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.12.1z3 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.12.1z4 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.12.1z5 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.12.1z6 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.12.2 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.12.2a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.12.3 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.12.3a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.12.4 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.12.4a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.12.4b CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.13.1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.13.1a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.14.1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.14.1a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.15.1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.15.1a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.15.1b CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.15.1w CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.15.1x CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.15.1y CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.15.1z CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.16.1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.16.1a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.2.1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.2.1a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.2.1r CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.2.1v CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.2.2 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.2.3 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.3.1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.3.1a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.3.1w CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.3.1x CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.3.1z CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.3.2 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.3.2a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.3.3 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.3.4 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.3.4a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.3.4b CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.3.4c CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.3.5 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.3.5a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.3.5b CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.3.6 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.3.7 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.3.8 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.3.8a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.4.1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.4.1a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.4.1b CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.4.2 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.4.2a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.5.1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.5.1a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.6.1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.6.1a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.6.1w CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.6.1x CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.6.1y CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.6.1z CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.6.1z1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.6.2 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.6.3 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.6.3a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.6.4 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.6.5 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.6.5a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.6.6 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.6.6a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.6.7 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.6.8 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.6.8a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.7.1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.7.1a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.7.1b CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.7.2 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.8.1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.8.1a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.9.1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.9.1a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.9.1w CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.9.1x CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.9.1x1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.9.1y CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.9.1y1 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.9.2 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.9.2a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.9.3 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.9.3a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.9.4 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.9.4a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.9.5 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.9.5a CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.9.5b CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.9.5e CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.9.5f CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.9.6 CVEProject cvelistV5 (CNA)
Cisco Cisco IOS XE Software 17.9.6a CVEProject cvelistV5 (CNA)

References and advisories

1
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Details

Published
2026-03-25
Last updated
2026-03-26
State
Published
Assigner (CNA)
cisco

Exploit prediction (EPSS)

0.18%
Probability of exploitation in 30 days
8.4%
Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable
No
Exploitation
None
Technical impact
Partial

Weaknesses (CWE)

  • CWE-771
    Missing Reference to Active Allocated Resource