CVE-2019-16027

mediumpriority · track · 27EPSS 0.015 · 74 %ileEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

1.51% (74th) EPSS

CVSS 4 · medium

Is it mine?

20 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · cisco_csaf

EPSS · scored 2026-10-27

A vulnerability in the implementation of the Intermediate System–to–Intermediate System (IS–IS) routing protocol functionality in Cisco IOS XR Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition in the IS–IS process. The vulnerability is due to improper handling of a Simple Network Management Protocol (SNMP) request for specific Object Identifiers (OIDs) by the IS–IS process. An attacker could exploit this vulnerability by sending a crafted SNMP request to the affected device. A successful exploit could allow the attacker to cause a DoS condition in the IS–IS process.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedCisco IOS XR Softwarecisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com

cvss

Technical severity, 0–10. One row per scoring source.

7.7

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4–7.7

v2.04mediumAV:N/AC:L/Au:S/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 8 · impact 2.9

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 2.8 · impact 3.6

v3.07.7highCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:Hsecondary · ENISA EU

v3.07.7highCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:Hsecondary · psirt@cisco.com USexploitability 3.1 · impact 4

v3.07.7highCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:Hsecondary · Cisco PSIRT US

v3.17.7highAV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU

v3.16mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-20USprimaryCWE-20US

affected products (20)

Products and version ranges known to be affected.

Cisco Cisco IOS XR Softwareall versionscisco_csafUS
Cisco Cisco IOS XR Softwareunspecified → n/aenisa_euvdEU
Cisco Systems Inc. Cisco IOS XR≤ 6.6.3fstec_bduRU
cisco ios xr= 4.3.2nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr= 5.2.5nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr= 6.1.2nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr= 6.1.3nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr= 6.1.4nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr= 6.2.2nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr= 6.2.25nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr= 6.2.3nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr= 6.3.15nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr= 6.3.2nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr= 6.3.3nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr= 6.4.2nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr= 6.5.2nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr= 6.5.3nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr= 6.6.1nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr= 6.6.2nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cisco ios xr= 6.6.25nvdUScpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*

advisories (1)

Vendor and ecosystem advisories describing this.

cisco-sa-20200122-ios-xr-dosCisco IOS XR Software Intermediate System-to-Intermediate System Denial of Service Vulnerability2020-01-22csaf · cisco_csafUS
A vulnerability in the implementation of the Intermediate System-to-Intermediate System (IS-IS) routing protocol functionality in Cisco IOS XR Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition in the IS-IS process. The vulnerability is due to improper handling of a Simple Network Management Protocol (SNMP) request for specific Object Identifiers (OIDs) by the IS-IS process. An attacker could exploit this vulnerability by sending a crafted SNMP request to the affected device. A successful exploit could allow the attacker to cause a DoS condition in the IS-IS process. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200122-ios-xr-dos ["https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200122-ios-xr-dos"]

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cisco_csaf nvd NVD CVE.org MITRE

published 2020-01-26modified 2026-06-17

related (25,173)

Related entries.

ID	severity	EPSS	exploitable	published
CVE-2026-88771US	critical9.8OT critical	82.2% (100th)	KEV	2026-09-27
Improper input validation vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway. This issue affects ADC: before 14.1-73.37, before 13.1-64.23, before 14.1-73.37 FIPS,…
CVE-2026-93952US	—OT critical	1.38% (72nd)	KEV	2026-09-22
VeloCloud Orchestrator (VCO) on-prem has a security issue where this issue may allow a remote attacker to access privileged internal functionality and impact the VCO host. Successf…
CVE-2026-12569US	critical9.8OT critical	46.0% (99th)	KEV	2026-06-18
A critical remote code execution (RCE) vulnerability has been reported in PTC Windchill PDMlink and PTC FlexPLM. The vulnerability may be exploited through the deserialization of u…
CVE-2026-34910US	—OT critical	90.0% (100th)	KEV	2026-05-22
A malicious actor with access to the network could exploit an Improper Input Validation vulnerability found in UniFi OS devices to execute a Command Injection.
CVE-2026-6973US	—OT critical	34.5% (98th)	KEV	2026-05-07
An Improper Input Validation in Ivanti EPMM before versions 12.6.1.1, 12.7.0.1, and 12.8.0.1 allows a remotely authenticated user with administrative access to achieve remote code…

+25168 more

references (8)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan