Is CVE-2024-20436 being actively exploited?

CVE-2024-20436 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2024-20436?

CVE-2024-20436 has a CVSS 3.1 base score of 8.6 (HIGH).

CVE-2024-20436

HIGH · CVSS 8.6EPSS 0.9%EU EUVD

A vulnerability in the HTTP Server feature of Cisco IOS XE Software when the Telephony Service feature is enabled could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to a null pointer dereference when accessing specific URLs. An attacker could exploit this vulnerability by sending crafted HTTP traffic to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, causing a DoS condition on the affected device.

Key facts

CVSS score: 8.6 (v3.1)
Severity: HIGH
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Weakness (CWE): CWE-476
EPSS score: 0.9% (58th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2024-18151)
Published: September 25, 2024
NVD last modified: June 17, 2026
Status: Analyzed

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2024-18151 in the EU Vulnerability Database. Last updated in EUVD on September 25, 2024.

View on the EU Vulnerability Database

Affected products

cisco / ios xe
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and 151 more…

Certified products that may be affected

8 FIPS 140 or Common Criteria certified products, from automated matching by sec-certs.org.

Cisco Embedded Services 9300 and 3300 Series Switches (ESS9300 & ESS3300) running IOS-XE 17.12 - Cisco Systems, Inc. - Common Criteria CCEVS-VR-VID-11521-2025 - active
Cisco cEdge Routers running IOS XE 17.12 with SD-WAN 20.12 - Cisco Systems, Inc. - Common Criteria 654-LSS - active
Cisco Catalyst Industrial Ethernet 3100 (IE3100) Rugged Series Switches running IOS-XE 17.12 - Cisco Systems, Inc. - Common Criteria CCEVS-VR-VID-11490-2024 - archived
Cisco Catalyst Industrial Ethernet 9300 Rugged Series Switches running IOS-XE 17.12 - Cisco Systems, Inc. - Common Criteria CCEVS-VR-VID-11466-2024 - archived
Cisco Catalyst Industrial Ethernet 3200, 3300, 3400, 3400H (IE3x00) Rugged Series Switches running IOS-XE 17.12 - Cisco Systems, Inc. - Common Criteria CCEVS-VR-VID-11443-2024 - archived

See all 8 in the Security Certifications Explorer.

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-httpsrvr-dos-yOZThut(Vendor Advisory)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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