Vulnerability-Lookup

CVE-2026-20074 (GCVE-0-2026-20074)

Vulnerability from cvelistv5 – Published: 2026-03-11 16:31 – Updated: 2026-03-11 17:20

Title

Cisco IOS XR Software Multi-Instance Intermediate System-to-Intermediate System Denial of Service Vulnerability

Summary

A vulnerability in the Intermediate System-to-Intermediate System (IS-IS) multi-instance routing feature of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to cause the IS-IS process to restart unexpectedly. This vulnerability is due to insufficient input validation of ingress IS-IS packets. An attacker could exploit this vulnerability by sending crafted IS-IS packets to an affected device after forming an adjacency. A successful exploit could allow the attacker to cause the IS-IS process to restart unexpectedly, resulting in a temporary loss of connectivity to advertised networks and a denial of service (DoS) condition. Note: The IS-IS protocol is a routing protocol. To exploit this vulnerability, an attacker must be Layer 2-adjacent to the affected device and must have formed an adjacency.

Severity

7.4 (High)


                        
                          CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-03-11 17:04 UTC

CWE

CWE-1287 - Improper Validation of Specified Type of Input

Assigner

cisco mitre root

References

1 reference

URL	Tags
https://sec.cloudapps.cisco.com/security/center/c…

Impacted products

1 product

Vendor	Product	Version	CPE status
Cisco	Cisco IOS XR Software	Affected: 7.8.1 Affected: 7.9.1 Affected: 7.10.1 Affected: 7.8.2 Affected: 7.8.22 Affected: 7.9.2 Affected: 7.11.1 Affected: 7.9.21 Affected: 7.10.2 Affected: 24.1.1 Affected: 7.11.2 Affected: 24.2.1 Affected: 24.1.2 Affected: 24.2.11 Affected: 24.3.1 Affected: 24.4.1 Affected: 24.2.2 Affected: 7.8.23 Affected: 7.11.21 Affected: 24.2.20 Affected: 24.3.2 Affected: 24.4.10 Affected: 25.1.1 Affected: 24.4.2 Affected: 24.3.20 Affected: 24.4.15 Affected: 25.2.1 Affected: 25.1.2 Affected: 24.3.30 Affected: 24.4.30 Affected: 24.2.21 Affected: 25.2.15	guessed

Show details on NVD website

JSON

To clipboard

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                "id": "CVE-2026-20074",
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Un exploit exitoso podr\u00eda permitir al atacante causar que el proceso IS-IS se reinicie inesperadamente, lo que resultar\u00eda en una p\u00e9rdida temporal de conectividad a las redes anunciadas y una condici\u00f3n de denegaci\u00f3n de servicio (DoS).\\nNota: El protocolo IS-IS es un protocolo de enrutamiento. 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}

BDU:2026-05200 (CVE-2026-20074)

Vulnerability from fstec – Published: 2026-04-14 – Updated: 2026-04-14 – View on bdu.fstec.ru Fixed

Title

Уязвимость реализации протокола маршрутизации промежуточной системы (IS-IS) операционных систем Cisco IOS XR, позволяющая нарушителю вызвать отказ в обслуживании

Summary

Уязвимость реализации протокола маршрутизации промежуточной системы (IS-IS) операционных систем Cisco IOS XR связана с неправильной проверкой указанного типа входных данных. Эксплуатация уязвимости может позволить нарушителю, действующему удаленно, вызвать отказ в обслуживании

Severity

6.1 (Medium) CVSS 2.0


                      
                        AV:A/AC:L/Au:N/C:N/I:N/A:C

7.4 (High) CVSS 3.1


                      
                        CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Class

Code vulnerability

Status

Confirmed by the vendor

Exploitation

Resource manipulation

Incidents

Being clarified

Remediation

Software update

CWE

CWE-1287 - Недостаточная проверка заданного типа входных данных

Aliases

CVE-2026-20074, CISCO-SA-ISIS-DOS-KDMXPSZK

References

1 reference

URL
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/c…

Impacted products

1 product from 2 vendors

Vendors

Cisco Systems, Inc.

Products

Cisco IOS XR

Versions

до 25.2.2 (Cisco IOS XR), до 25.3.1 (Cisco IOS XR), до 7.8 (Cisco IOS XR), до 7.9 (Cisco IOS XR), до 7.10 (Cisco IOS XR), до 7.11 (Cisco IOS XR), до 24.1 (Cisco IOS XR), до 24.2 (Cisco IOS XR), до 24.3 (Cisco IOS XR), до 24.4 (Cisco IOS XR)

Product types

Operating system

Platforms

Cisco Systems, Inc. Cisco IOS XR до 25.2.2, Inc. Cisco IOS XR до 25.3.1, Inc. Cisco IOS XR до 7.8, Inc. Cisco IOS XR до 7.9, Inc. Cisco IOS XR до 7.10, Inc. Cisco IOS XR до 7.11, Inc. Cisco IOS XR до 24.1, Inc. Cisco IOS XR до 24.2, Inc. Cisco IOS XR до 24.3, Inc. Cisco IOS XR до 24.4

Mitigations

Использование рекомендаций производителя: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-isis-dos-kDMxpSzK

JSON

To clipboard

{
  "CVSS 2.0": "AV:A/AC:L/Au:N/C:N/I:N/A:C",
  "CVSS 3.0": "AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H",
  "CVSS 4.0": null,
  "remediation_\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": null,
  "remediation_\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435": null,
  "\u0412\u0435\u043d\u0434\u043e\u0440 \u041f\u041e": "Cisco Systems, Inc.",
  "\u0412\u0435\u0440\u0441\u0438\u044f \u041f\u041e": "\u0434\u043e 25.2.2 (Cisco IOS XR), \u0434\u043e 25.3.1 (Cisco IOS XR), \u0434\u043e 7.8 (Cisco IOS XR), \u0434\u043e 7.9 (Cisco IOS XR), \u0434\u043e 7.10 (Cisco IOS XR), \u0434\u043e 7.11 (Cisco IOS XR), \u0434\u043e 24.1 (Cisco IOS XR), \u0434\u043e 24.2 (Cisco IOS XR), \u0434\u043e 24.3 (Cisco IOS XR), \u0434\u043e 24.4 (Cisco IOS XR)",
  "\u0412\u043e\u0437\u043c\u043e\u0436\u043d\u044b\u0435 \u043c\u0435\u0440\u044b \u043f\u043e \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u044e": "\u0418\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u0435 \u0440\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0430\u0446\u0438\u0439 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u0435\u043b\u044f:\nhttps://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-isis-dos-kDMxpSzK",
  "\u0414\u0430\u0442\u0430 \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0438\u044f": "11.03.2026",
  "\u0414\u0430\u0442\u0430 \u043f\u043e\u0441\u043b\u0435\u0434\u043d\u0435\u0433\u043e \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u044f": "14.04.2026",
  "\u0414\u0430\u0442\u0430 \u043f\u0443\u0431\u043b\u0438\u043a\u0430\u0446\u0438\u0438": "14.04.2026",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": "BDU:2026-05200",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440\u044b \u0434\u0440\u0443\u0433\u0438\u0445 \u0441\u0438\u0441\u0442\u0435\u043c \u043e\u043f\u0438\u0441\u0430\u043d\u0438\u0439 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "CVE-2026-20074, CISCO-SA-isis-dos-kDMxpSzK",
  "\u0418\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f \u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0430",
  "\u041a\u043b\u0430\u0441\u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043a\u043e\u0434\u0430",
  "\u041d\u0430\u0437\u0432\u0430\u043d\u0438\u0435 \u041f\u041e": "Cisco IOS XR",
  "\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435 \u041e\u0421 \u0438 \u0442\u0438\u043f \u0430\u043f\u043f\u0430\u0440\u0430\u0442\u043d\u043e\u0439 \u043f\u043b\u0430\u0442\u0444\u043e\u0440\u043c\u044b": "Cisco Systems, Inc. Cisco IOS XR \u0434\u043e 25.2.2 , Cisco Systems, Inc. Cisco IOS XR \u0434\u043e 25.3.1 , Cisco Systems, Inc. Cisco IOS XR \u0434\u043e 7.8 , Cisco Systems, Inc. Cisco IOS XR \u0434\u043e 7.9 , Cisco Systems, Inc. Cisco IOS XR \u0434\u043e 7.10 , Cisco Systems, Inc. Cisco IOS XR \u0434\u043e 7.11 , Cisco Systems, Inc. Cisco IOS XR \u0434\u043e 24.1 , Cisco Systems, Inc. Cisco IOS XR \u0434\u043e 24.2 , Cisco Systems, Inc. Cisco IOS XR \u0434\u043e 24.3 , Cisco Systems, Inc. Cisco IOS XR \u0434\u043e 24.4 ",
  "\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0440\u0435\u0430\u043b\u0438\u0437\u0430\u0446\u0438\u0438 \u043f\u0440\u043e\u0442\u043e\u043a\u043e\u043b\u0430 \u043c\u0430\u0440\u0448\u0440\u0443\u0442\u0438\u0437\u0430\u0446\u0438\u0438 \u043f\u0440\u043e\u043c\u0435\u0436\u0443\u0442\u043e\u0447\u043d\u043e\u0439 \u0441\u0438\u0441\u0442\u0435\u043c\u044b (IS-IS) \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u043e\u043d\u043d\u044b\u0445 \u0441\u0438\u0441\u0442\u0435\u043c Cisco IOS XR, \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u043d\u0430\u0440\u0443\u0448\u0438\u0442\u0435\u043b\u044e \u0432\u044b\u0437\u0432\u0430\u0442\u044c \u043e\u0442\u043a\u0430\u0437 \u0432 \u043e\u0431\u0441\u043b\u0443\u0436\u0438\u0432\u0430\u043d\u0438\u0438",
  "\u041d\u0430\u043b\u0438\u0447\u0438\u0435 \u044d\u043a\u0441\u043f\u043b\u043e\u0439\u0442\u0430": "\u0414\u0430\u043d\u043d\u044b\u0435 \u0443\u0442\u043e\u0447\u043d\u044f\u044e\u0442\u0441\u044f",
  "\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435 \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "\u041d\u0435\u0434\u043e\u0441\u0442\u0430\u0442\u043e\u0447\u043d\u0430\u044f \u043f\u0440\u043e\u0432\u0435\u0440\u043a\u0430 \u0437\u0430\u0434\u0430\u043d\u043d\u043e\u0433\u043e \u0442\u0438\u043f\u0430 \u0432\u0445\u043e\u0434\u043d\u044b\u0445 \u0434\u0430\u043d\u043d\u044b\u0445 (CWE-1287)",
  "\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0440\u0435\u0430\u043b\u0438\u0437\u0430\u0446\u0438\u0438 \u043f\u0440\u043e\u0442\u043e\u043a\u043e\u043b\u0430 \u043c\u0430\u0440\u0448\u0440\u0443\u0442\u0438\u0437\u0430\u0446\u0438\u0438 \u043f\u0440\u043e\u043c\u0435\u0436\u0443\u0442\u043e\u0447\u043d\u043e\u0439 \u0441\u0438\u0441\u0442\u0435\u043c\u044b (IS-IS) \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u043e\u043d\u043d\u044b\u0445 \u0441\u0438\u0441\u0442\u0435\u043c Cisco IOS XR \u0441\u0432\u044f\u0437\u0430\u043d\u0430 \u0441 \u043d\u0435\u043f\u0440\u0430\u0432\u0438\u043b\u044c\u043d\u043e\u0439 \u043f\u0440\u043e\u0432\u0435\u0440\u043a\u043e\u0439 \u0443\u043a\u0430\u0437\u0430\u043d\u043d\u043e\u0433\u043e \u0442\u0438\u043f\u0430 \u0432\u0445\u043e\u0434\u043d\u044b\u0445 \u0434\u0430\u043d\u043d\u044b\u0445. \u042d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u044f \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 \u043c\u043e\u0436\u0435\u0442 \u043f\u043e\u0437\u0432\u043e\u043b\u0438\u0442\u044c \u043d\u0430\u0440\u0443\u0448\u0438\u0442\u0435\u043b\u044e, \u0434\u0435\u0439\u0441\u0442\u0432\u0443\u044e\u0449\u0435\u043c\u0443 \u0443\u0434\u0430\u043b\u0435\u043d\u043d\u043e, \u0432\u044b\u0437\u0432\u0430\u0442\u044c \u043e\u0442\u043a\u0430\u0437 \u0432 \u043e\u0431\u0441\u043b\u0443\u0436\u0438\u0432\u0430\u043d\u0438\u0438",
  "\u041f\u043e\u0441\u043b\u0435\u0434\u0441\u0442\u0432\u0438\u044f \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": null,
  "\u041f\u0440\u043e\u0447\u0430\u044f \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f": null,
  "\u0421\u0432\u044f\u0437\u044c \u0441 \u0438\u043d\u0446\u0438\u0434\u0435\u043d\u0442\u0430\u043c\u0438 \u0418\u0411": "\u0414\u0430\u043d\u043d\u044b\u0435 \u0443\u0442\u043e\u0447\u043d\u044f\u044e\u0442\u0441\u044f",
  "\u0421\u043e\u0441\u0442\u043e\u044f\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041e\u043f\u0443\u0431\u043b\u0438\u043a\u043e\u0432\u0430\u043d\u0430",
  "\u0421\u043f\u043e\u0441\u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u044f": "\u041e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u0435 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f",
  "\u0421\u043f\u043e\u0441\u043e\u0431 \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438": "\u041c\u0430\u043d\u0438\u043f\u0443\u043b\u0438\u0440\u043e\u0432\u0430\u043d\u0438\u0435 \u0440\u0435\u0441\u0443\u0440\u0441\u0430\u043c\u0438",
  "\u0421\u0441\u044b\u043b\u043a\u0438 \u043d\u0430 \u0438\u0441\u0442\u043e\u0447\u043d\u0438\u043a\u0438": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-isis-dos-kDMxpSzK",
  "\u0421\u0442\u0430\u0442\u0443\u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041f\u043e\u0434\u0442\u0432\u0435\u0440\u0436\u0434\u0435\u043d\u0430 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u0435\u043b\u0435\u043c",
  "\u0422\u0438\u043f \u041f\u041e": "\u041e\u043f\u0435\u0440\u0430\u0446\u0438\u043e\u043d\u043d\u0430\u044f \u0441\u0438\u0441\u0442\u0435\u043c\u0430",
  "\u0422\u0438\u043f \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "CWE-1287",
  "\u0423\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0421\u0440\u0435\u0434\u043d\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 (\u0431\u0430\u0437\u043e\u0432\u0430\u044f \u043e\u0446\u0435\u043d\u043a\u0430 CVSS 2.0 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 6,1)\n\u0412\u044b\u0441\u043e\u043a\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 (\u0431\u0430\u0437\u043e\u0432\u0430\u044f \u043e\u0446\u0435\u043d\u043a\u0430 CVSS 3.1 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 7,4)"
}

CERTFR-2026-AVI-0279

Vulnerability from certfr_avis - Published: 2026-03-12 - Updated: 2026-03-12

De multiples vulnérabilités ont été découvertes dans Cisco IOS XR. Certaines d'entre elles permettent à un attaquant de provoquer une élévation de privilèges et un déni de service à distance.

L'éditeur fournit des recommandations dans l'attente de la publication de nouvelles versions applicatives.

Solutions

Se référer au bulletin de sécurité de l'éditeur pour l'obtention des correctifs (cf. section Documentation).

Impacted products

	Vendor	Product	Description
	Cisco	N/A	IOS XR Software versions postérieures à 25.3 et antérieures à 25.4.2
	Cisco	N/A	IOS XR Software versions postérieures à 7.7 et antérieures à 25.2.2

References

Title

Publication Time

CISCO-SA-ISIS-DOS-KDMXPSZK

Vulnerability from csaf_cisco - Published: 2026-03-11 16:00 - Updated: 2026-03-11 16:00

Summary

Cisco IOS XR Software Multi-Instance Intermediate System-to-Intermediate System Denial of Service Vulnerability

Scope

1 vulnerability in this advisory, including CVE-2026-20074.

CVE-2026-20074

7.4 (High)


                
                  CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Known affected: 1 product

https://software.cisco.com

Open the full advisory

FKIE_CVE-2026-20074

Vulnerability from fkie_nvd - Published: 2026-03-11 17:16 - Updated: 2026-07-08 19:07

Severity

7.4 (High) - CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Summary

References

	URL	Tags
	psirt@cisco.com	https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-isis-dos-kDMxpSzK	Mitigation, Vendor Advisory

Impacted products

	Vendor	Product	Version
	cisco	ios_xr	*
	cisco	ios_xr	25.3.0

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unknown",
          "product": "Cisco IOS XR Software",
          "vendor": "Cisco",
          "versions": [
            {
              "status": "affected",
              "version": "7.8.1"
            },
            {
              "status": "affected",
              "version": "7.9.1"
            },
            {
              "status": "affected",
              "version": "7.10.1"
            },
            {
              "status": "affected",
              "version": "7.8.2"
            },
            {
              "status": "affected",
              "version": "7.8.22"
            },
            {
              "status": "affected",
              "version": "7.9.2"
            },
            {
              "status": "affected",
              "version": "7.11.1"
            },
            {
              "status": "affected",
              "version": "7.9.21"
            },
            {
              "status": "affected",
              "version": "7.10.2"
            },
            {
              "status": "affected",
              "version": "24.1.1"
            },
            {
              "status": "affected",
              "version": "7.11.2"
            },
            {
              "status": "affected",
              "version": "24.2.1"
            },
            {
              "status": "affected",
              "version": "24.1.2"
            },
            {
              "status": "affected",
              "version": "24.2.11"
            },
            {
              "status": "affected",
              "version": "24.3.1"
            },
            {
              "status": "affected",
              "version": "24.4.1"
            },
            {
              "status": "affected",
              "version": "24.2.2"
            },
            {
              "status": "affected",
              "version": "7.8.23"
            },
            {
              "status": "affected",
              "version": "7.11.21"
            },
            {
              "status": "affected",
              "version": "24.2.20"
            },
            {
              "status": "affected",
              "version": "24.3.2"
            },
            {
              "status": "affected",
              "version": "24.4.10"
            },
            {
              "status": "affected",
              "version": "25.1.1"
            },
            {
              "status": "affected",
              "version": "24.4.2"
            },
            {
              "status": "affected",
              "version": "24.3.20"
            },
            {
              "status": "affected",
              "version": "24.4.15"
            },
            {
              "status": "affected",
              "version": "25.2.1"
            },
            {
              "status": "affected",
              "version": "25.1.2"
            },
            {
              "status": "affected",
              "version": "24.3.30"
            },
            {
              "status": "affected",
              "version": "24.4.30"
            },
            {
              "status": "affected",
              "version": "24.2.21"
            },
            {
              "status": "affected",
              "version": "25.2.15"
            }
          ]
        }
      ],
      "source": "psirt@cisco.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "8352E25F-6467-4428-B677-013F64C9F130",
              "versionEndExcluding": "25.2.2",
              "versionStartIncluding": "7.8.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:cisco:ios_xr:25.3.0:*:*:*:*:*:*:*",
              "matchCriteriaId": "1B34524C-985A-421D-91D8-3447294A44B3",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "A vulnerability in the Intermediate System-to-Intermediate System (IS-IS) multi-instance routing feature of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to cause the IS-IS process to restart unexpectedly.\r\n\r\nThis vulnerability is due to insufficient input validation of ingress IS-IS packets. An attacker could exploit this vulnerability by sending crafted IS-IS packets to an affected device after forming an adjacency. A successful exploit could allow the attacker to cause the IS-IS process to restart unexpectedly, resulting in a temporary loss of connectivity to advertised networks and a denial of service (DoS) condition.\r\nNote: The IS-IS protocol is a routing protocol. To exploit this vulnerability, an attacker must be Layer 2-adjacent to the affected device and must have formed an adjacency.\u0026nbsp;\u0026nbsp;"
    },
    {
      "lang": "es",
      "value": "Una vulnerabilidad en la funci\u00f3n de enrutamiento multi-instancia de Intermediate System-to-Intermediate System (IS-IS) de Cisco IOS XR Software podr\u00eda permitir a un atacante no autenticado y adyacente causar que el proceso IS-IS se reinicie inesperadamente.\n\nEsta vulnerabilidad se debe a una validaci\u00f3n de entrada insuficiente de los paquetes IS-IS de entrada. Un atacante podr\u00eda explotar esta vulnerabilidad enviando paquetes IS-IS manipulados a un dispositivo afectado despu\u00e9s de formar una adyacencia. Un exploit exitoso podr\u00eda permitir al atacante causar que el proceso IS-IS se reinicie inesperadamente, lo que resultar\u00eda en una p\u00e9rdida temporal de conectividad a las redes anunciadas y una condici\u00f3n de denegaci\u00f3n de servicio (DoS).\nNota: El protocolo IS-IS es un protocolo de enrutamiento. Para explotar esta vulnerabilidad, un atacante debe ser adyacente en Capa 2 al dispositivo afectado y debe haber formado una adyacencia."
    }
  ],
  "id": "CVE-2026-20074",
  "lastModified": "2026-07-08T19:07:12.303",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "ADJACENT_NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.4,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 4.0,
        "source": "psirt@cisco.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-20074",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-03-11T17:04:46.266844Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-03-11T17:16:55.470",
  "references": [
    {
      "source": "psirt@cisco.com",
      "tags": [
        "Mitigation",
        "Vendor Advisory"
      ],
      "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-isis-dos-kDMxpSzK"
    }
  ],
  "sourceIdentifier": "psirt@cisco.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-1287"
        }
      ],
      "source": "psirt@cisco.com",
      "type": "Secondary"
    }
  ]
}

GHSA-95M8-QGXC-HCQX

Vulnerability from github – Published: 2026-03-11 18:30 – Updated: 2026-03-11 18:30

Details

This vulnerability is due to insufficient input validation of ingress IS-IS packets. An attacker could exploit this vulnerability by sending crafted IS-IS packets to an affected device after forming an adjacency. A successful exploit could allow the attacker to cause the IS-IS process to restart unexpectedly, resulting in a temporary loss of connectivity to advertised networks and a denial of service (DoS) condition. Note: The IS-IS protocol is a routing protocol. To exploit this vulnerability, an attacker must be Layer 2-adjacent to the affected device and must have formed an adjacency.

Severity

7.4 (High)


                  
                    CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-20074"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1287"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-03-11T17:16:55Z",
    "severity": "HIGH"
  },
  "details": "A vulnerability in the Intermediate System-to-Intermediate System (IS-IS) multi-instance routing feature of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to cause the IS-IS process to restart unexpectedly.\n\nThis vulnerability is due to insufficient input validation of ingress IS-IS packets. An attacker could exploit this vulnerability by sending crafted IS-IS packets to an affected device after forming an adjacency. A successful exploit could allow the attacker to cause the IS-IS process to restart unexpectedly, resulting in a temporary loss of connectivity to advertised networks and a denial of service (DoS) condition.\nNote: The IS-IS protocol is a routing protocol. To exploit this vulnerability, an attacker must be Layer 2-adjacent to the affected device and must have formed an adjacency.\u0026nbsp;\u0026nbsp;",
  "id": "GHSA-95m8-qgxc-hcqx",
  "modified": "2026-03-11T18:30:33Z",
  "published": "2026-03-11T18:30:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-20074"
    },
    {
      "type": "WEB",
      "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-isis-dos-kDMxpSzK"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

NCSC-2026-0094

Vulnerability from csaf_ncscnl - Published: 2026-03-12 14:44 - Updated: 2026-03-12 14:44

Summary

Kwetsbaarheden verholpen in Cisco IOS XR

Scope

4 vulnerabilities in this advisory, including CVE-2026-20074.

CVE-2026-20074

A vulnerability in Cisco IOS XR's IS-IS multi-instance routing feature allows an unauthenticated, adjacent attacker to cause unexpected IS-IS process restarts by sending crafted packets, resulting in temporary network disruption and denial of service.

7.4 (High)


                
                  CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Known affected: 1 product

Open the full advisory

WID-SEC-W-2026-0706

Vulnerability from csaf_certbund - Published: 2026-03-11 23:00 - Updated: 2026-03-11 23:00

Summary

Cisco IOS XR: Mehrere Schwachstellen

Severity

Hoch

Scope

4 vulnerabilities in this advisory, including CVE-2026-20074.

CVE-2026-20074

Known affected: 2 products

Open the full advisory

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

CVE-2026-20074 (GCVE-0-2026-20074)

BDU:2026-05200 (CVE-2026-20074)

CERTFR-2026-AVI-0279

Solutions

CISCO-SA-ISIS-DOS-KDMXPSZK

FKIE_CVE-2026-20074

GHSA-95M8-QGXC-HCQX

NCSC-2026-0094

WID-SEC-W-2026-0706

Tags

Sightings

Nomenclature

Related by attack behaviour