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CVE-2026-20127 — Cisco Catalyst SD-WAN Controller Authentication Bypass Vulnerability

CVE-2026-20127 · Cisco Catalyst SD-WAN Manager · CVSS 10 · KEV

In brief

Severity · CVSS
Critical10CVSS 3.1, Critical
EPSS
88%
CISA KEV
Known exploited, listed since 25 Feb 2026
Vendor
Cisco
Published · Modified
·
Last verified

Summary

A vulnerability in the peering authentication in Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart, Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, and Cisco Catalyst SD-WAN Validator, formerly SD-WAN vBond, could allow an unauthenticated, remote attacker to bypass authentication and obtain administrative privileges on an affected system. This vulnerability exists because the peering authentication mechanism in an affected system is not working properly. An attacker could exploit this vulnerability by sending crafted requests to an affected system. A successful exploit could allow the attacker to log in to an affected Cisco Catalyst SD-WAN Controller as an internal, high-privileged, non-root user account. Using this account, the attacker could access NETCONF, which would then allow the attacker to manipulate network configuration for the SD-WAN fabric. 

Weakness: CWE-287

Title, description and the vendor's statements are quoted from the CVE record; a vendor's advisory is summarised in Patcharo's words, with a link.

Affected and fixed versions

Per product and release branch, as the vendor's CVE record and official advisory state them. A fixed release is shown only when a document names it: the vendor's, or CERT-FR's for Check Point, with its source.

4 branches with a published fixed release · 19 branches to migrate · 1 branch without a precise fixed release

Cisco Catalyst SD-WAN Manager

Source: cisco-sa-sdwan-rpa-EHchtZkCVE-2026-20127

  1. 20.18
    Affected versions20.18.1, 20.18.2
    First fixed release20.18.2.1
  2. 20.16
    Affected versions20.16.1
    First fixed releaseMigration to a fixed release requiredTarget: 20.18.2.1 or later
  3. 20.15
    Affected versions20.15.1, 20.15.2, 20.15.3, 20.15.3.1
    6 releases listed20.15.1, 20.15.2, 20.15.3, 20.15.3.1, 20.15.4, 20.15.4.1
    First fixed release20.15.4.2
  4. 20.14
    Affected versions20.14.1
    First fixed releaseMigration to a fixed release requiredTarget: 20.15.4.2 or later
  5. 20.13
    Affected versions20.13.1
    First fixed releaseMigration to a fixed release requiredTarget: 20.15.4.2 or later
  6. 20.12
    Affected versions20.12.1, 20.12.2, 20.12.3, 20.12.3.1
    16 releases listed20.12.1, 20.12.2, 20.12.3, 20.12.3.1, 20.12.4, 20.12.4.0.3, 20.12.4.0.4, 20.12.4.0.6, 20.12.4.1, 20.12.5, 20.12.5.1, 20.12.5.1.1, 20.12.5.2, 20.12.6, 20.12.401, 20.12.501
    First fixed release20.12.5.320.12.6.1
  7. 20.11
    Affected versions20.11.1, 20.11.1.1, 20.11.1.2
    First fixed releaseMigration to a fixed release requiredTarget: 20.12.6.1 or later
  8. 20.10
    Affected versions20.10.1, 20.10.1.1, 20.10.1.2
    First fixed releaseNot published in the sources followed
  9. 20.9
    Affected versions20.9.1, 20.9.1.1, 20.9.2, 20.9.2.0.1
    49 releases listed20.9.1, 20.9.1.1, 20.9.2, 20.9.2.0.1, 20.9.2.1, 20.9.2.2, 20.9.2.3, 20.9.3, 20.9.3.0.2, 20.9.3.0.3, 20.9.3.0.4, 20.9.3.0.5, 20.9.3.0.7, 20.9.3.0.8, 20.9.3.0.12, 20.9.3.0.16, 20.9.3.0.17, 20.9.3.0.18, 20.9.3.0.20, 20.9.3.0.21, 20.9.3.0.23, 20.9.3.0.24, 20.9.3.0.25, 20.9.3.0.26, 20.9.3.0.29, 20.9.3.1, 20.9.3.2, 20.9.4, 20.9.4.0.4, 20.9.4.1, 20.9.4.1.1, 20.9.4.1.3, 20.9.4.1.6, 20.9.5, 20.9.5.1, 20.9.5.1.4, 20.9.5.2, 20.9.5.2.1, 20.9.5.2.7, 20.9.5.2.13, 20.9.5.2.14, 20.9.5.2.16, 20.9.5.2.21, 20.9.5.3, 20.9.6, 20.9.6.0.3, 20.9.7, 20.9.7.1, 20.9.8
    First fixed release20.9.8.2
  10. 20.8
    Affected versions20.8.1
    First fixed releaseMigration to a fixed release required
  11. 20.7
    Affected versions20.7.1, 20.7.1.0.2, 20.7.1.1, 20.7.2
    First fixed releaseMigration to a fixed release required
  12. 20.6
    Affected versions20.6.0.18.3, 20.6.0.18.4, 20.6.1, 20.6.1.0.1
    74 releases listed20.6.0.18.3, 20.6.0.18.4, 20.6.1, 20.6.1.0.1, 20.6.1.1, 20.6.1.2, 20.6.2, 20.6.2.0.4, 20.6.2.1, 20.6.2.2, 20.6.2.2.2, 20.6.2.2.3, 20.6.2.2.4, 20.6.2.2.7, 20.6.3, 20.6.3.0.2, 20.6.3.0.5, 20.6.3.0.7, 20.6.3.0.10, 20.6.3.0.11, 20.6.3.0.14, 20.6.3.0.18, 20.6.3.0.19, 20.6.3.0.23, 20.6.3.0.25, 20.6.3.0.27, 20.6.3.0.29, 20.6.3.0.31, 20.6.3.0.32, 20.6.3.0.33, 20.6.3.0.38, 20.6.3.0.39, 20.6.3.0.40, 20.6.3.0.41, 20.6.3.0.45, 20.6.3.0.46, 20.6.3.0.47, 20.6.3.0.51, 20.6.3.1, 20.6.3.1.1, 20.6.3.2, 20.6.3.3, 20.6.3.4, 20.6.4, 20.6.4.0.4, 20.6.4.0.19, 20.6.4.0.21, 20.6.4.1, 20.6.4.2, 20.6.5, 20.6.5.1, 20.6.5.1.2, 20.6.5.1.3, 20.6.5.1.4, 20.6.5.1.5, 20.6.5.1.6, 20.6.5.1.7, 20.6.5.1.9, 20.6.5.1.10, 20.6.5.1.11, 20.6.5.1.13, 20.6.5.1.14, 20.6.5.2, 20.6.5.2.1, 20.6.5.2.3, 20.6.5.2.4, 20.6.5.2.8, 20.6.5.3, 20.6.5.4, 20.6.5.5, 20.6.6, 20.6.6.0.1, 20.6.7, 20.6.8
    First fixed releaseMigration to a fixed release required
  13. 20.5
    Affected versions20.5.0.1.1, 20.5.1, 20.5.1.0.1, 20.5.1.0.2
    6 releases listed20.5.0.1.1, 20.5.1, 20.5.1.0.1, 20.5.1.0.2, 20.5.1.1, 20.5.1.2
    First fixed releaseMigration to a fixed release required
  14. 20.4
    Affected versions20.4.1, 20.4.1.0.1, 20.4.1.0.2, 20.4.1.1
    19 releases listed20.4.1, 20.4.1.0.1, 20.4.1.0.2, 20.4.1.1, 20.4.1.1.5, 20.4.1.2, 20.4.2, 20.4.2.0.1, 20.4.2.0.2, 20.4.2.0.4, 20.4.2.1, 20.4.2.1.1, 20.4.2.2, 20.4.2.2.1, 20.4.2.2.2, 20.4.2.2.3, 20.4.2.2.4, 20.4.2.2.8, 20.4.2.3
    First fixed releaseMigration to a fixed release required
  15. 20.3
    Affected versions20.3.1, 20.3.2, 20.3.2.0.5, 20.3.2.0.6
    50 releases listed20.3.1, 20.3.2, 20.3.2.0.5, 20.3.2.0.6, 20.3.2.1, 20.3.3, 20.3.3.0.2, 20.3.3.0.4, 20.3.3.0.8, 20.3.3.0.14, 20.3.3.0.16, 20.3.3.0.17, 20.3.3.0.18, 20.3.3.1, 20.3.3.1.1, 20.3.3.1.2, 20.3.3.1.5, 20.3.3.1.7, 20.3.3.1.10, 20.3.3.2, 20.3.4, 20.3.4.0.1, 20.3.4.0.5, 20.3.4.0.6, 20.3.4.0.9, 20.3.4.0.11, 20.3.4.0.19, 20.3.4.0.20, 20.3.4.0.24, 20.3.4.0.25, 20.3.4.0.26, 20.3.4.1, 20.3.4.1.1, 20.3.4.1.2, 20.3.4.2, 20.3.4.2.1, 20.3.4.2.2, 20.3.4.3, 20.3.5, 20.3.5.0.7, 20.3.5.0.8, 20.3.5.0.9, 20.3.5.1, 20.3.6, 20.3.7, 20.3.7.1, 20.3.7.2, 20.3.8, 20.3.813, 20.3.814
    First fixed releaseMigration to a fixed release required
  16. 20.1
    Affected versions20.1.1, 20.1.1.1, 20.1.2, 20.1.3
    6 releases listed20.1.1, 20.1.1.1, 20.1.2, 20.1.3, 20.1.3.1, 20.1.12
    First fixed releaseMigration to a fixed release required
  17. 19.3
    Affected versions19.3
    First fixed releaseMigration to a fixed release required
  18. 19.2
    Affected versions19.2, 19.2.1, 19.2.2, 19.2.3
    14 releases listed19.2, 19.2.1, 19.2.2, 19.2.3, 19.2.4, 19.2.4.0.1, 19.2.4.0.8, 19.2.4.0.9, 19.2.31, 19.2.32, 19.2.97, 19.2.98, 19.2.99, 19.2.929
    First fixed releaseMigration to a fixed release required
  19. 19.1
    Affected versions19.1
    First fixed releaseMigration to a fixed release required
  20. 19.0
    Affected versions19.0, 19.0.1a
    First fixed releaseMigration to a fixed release required
  21. 18.4
    Affected versions18.4, 18.4.0.1, 18.4.1, 18.4.3
    9 releases listed18.4, 18.4.0.1, 18.4.1, 18.4.3, 18.4.4, 18.4.5, 18.4.6, 18.4.302, 18.4.303
    First fixed releaseMigration to a fixed release required
  22. 18.3
    Affected versions18.3, 18.3.1, 18.3.1.1, 18.3.3
    11 releases listed18.3, 18.3.1, 18.3.1.1, 18.3.3, 18.3.3.1, 18.3.4, 18.3.5, 18.3.6, 18.3.6.1, 18.3.7, 18.3.8
    First fixed releaseMigration to a fixed release required
  23. 18.2
    Affected versions18.2
    First fixed releaseMigration to a fixed release required
  24. 17.2
    Affected versions17.2.4, 17.2.5, 17.2.6, 17.2.7
    7 releases listed17.2.4, 17.2.5, 17.2.6, 17.2.7, 17.2.8, 17.2.9, 17.2.10
    First fixed releaseMigration to a fixed release required

Remediation

Fix available

Vendor fix

  • Catalyst SD-WAN Manager 20.1820.18.2.1
  • Catalyst SD-WAN Manager 20.1520.15.4.2
  • Catalyst SD-WAN Manager 20.1220.12.5.3, 20.12.6.1
  • Catalyst SD-WAN Manager 20.920.9.8.2

Upgrade to a fixed release listed above for your branch, or to a later fixed release the vendor explicitly supports.

Branches without a fix of their own: migrate to a fixed release

  • Catalyst SD-WAN Manager 20.16 → 20.18.2.1
  • Catalyst SD-WAN Manager 20.14 → 20.15.4.2
  • Catalyst SD-WAN Manager 20.13 → 20.15.4.2
  • Catalyst SD-WAN Manager 20.11 → 20.12.6.1
  • Catalyst SD-WAN Manager 20.8
  • Catalyst SD-WAN Manager 20.7
  • Catalyst SD-WAN Manager 20.6
  • Catalyst SD-WAN Manager 20.5
  • Catalyst SD-WAN Manager 20.4
  • Catalyst SD-WAN Manager 20.3
  • Catalyst SD-WAN Manager 20.1
  • Catalyst SD-WAN Manager 19.3
  • Catalyst SD-WAN Manager 19.2
  • Catalyst SD-WAN Manager 19.1
  • Catalyst SD-WAN Manager 19.0
  • Catalyst SD-WAN Manager 18.4
  • Catalyst SD-WAN Manager 18.3
  • Catalyst SD-WAN Manager 18.2
  • Catalyst SD-WAN Manager 17.2

Cisco has released updates that fix this vulnerability; its advisory lists them.

SourceCisco Security Advisory cisco-sa-sdwan-rpa-EHchtZk

Mitigation (vendor)

Cisco describes a workaround or a mitigation in its advisory.

SourceCisco Security Advisory cisco-sa-sdwan-rpa-EHchtZk

CISA KEV required action

Please adhere to CISA’s guidelines to assess exposure and mitigate risks associated with Cisco SD-WAN devices as outlines in CISA’s Emergency Directive 26-03 (URL listed below in Notes) and CISA’s “Hunt & Hardening Guidance for Cisco SD-WAN Devices (URL listed below in Notes). Adhere to the applicable BOD 22-01 guidance for cloud services or discontinue use of the product if mitigations are not available.

CISA due date:

SourceCISA KEV

CERT-FR recommendation

[Update of 26 February 2026] The CERT-FR recommends conducting a compromise search based on the elements documented by Cisco in its security advisory and a blog post [1]: 1. Verification of the legitimacy of control connection peering events: * An example log is provided below.

Full text

The values associated with `peer-system-ip` and `public-ip` must correspond to expected values based on the information system architecture and SD-WAN configuration. Additionally, the `peer-type` must be consistent with the equipment linked to the `peer-system-ip` address. The timestamp of the event must be associated with maintenance or administration periods. Jul 26 22:03:33 vSmart-01 VDAEMON_0[2571]: %Viptela-vSmart-VDAEMON_0-5-NTCE-1000001: control-connection-state-change new-state:up peer-type:vmanage peer-system-ip:1.1.1.10 public-ip:192.168.3.20 public-port:12345 domain-id:1 site-id:1005 * Additionally, the CERT-FR advises correlating the information present in these events to identify reconnaissance patterns or persistent access attempts. For example, by grouping activities by `peer-type` and `peer-system-ip`. These logs may be present in `/var/log/tmplog/vdebug`, `/var/log/vsyslog`, `/var/log/jsyslog` or `/var/log/messages`. 2. Verification of the addition of an SSH authentication key for `vmanage-admin`: * The `vmanage-admin` account is a legitimate account used by the system. Attackers may have added an SSH key for this account and used it to connect to the equipment. * It is necessary to validate that authentication events related to the use of a public key for the `vmanage-admin` account can be linked to a known and legitimate IP address. These events are notably listed in …

SourceCERTFR-2026-ALE-002

CERT-FR recommendation

Refer to the vendor's security bulletin to obtain patches (see Documentation section).

SourceCERTFR-2026-AVI-0210

Last verified 1 Oct 2026 at 09:32 UTC

Known exploitation

Added to CISA KEV on 25 Feb 2026

Federal remediation due date: 27 Feb 2026

The CISA required action is shown under Remediation.

88% probability of exploitation in the next 30 days (percentile 100%).

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

CERT-FR

2 documents of the French national CERT (ANSSI) reference this CVE.

Alert (ALE)CERTFR-2026-ALE-002Published 25 Feb 2026 · updated 26 Mar 2026 · closed 26 Mar 2026

[Update] Vulnerability in Cisco Catalyst SD-WAN

Security policy bypass

Summary

A vulnerability has been discovered in Cisco Catalyst SD-WAN. It allows an attacker to cause a security policy bypass. Cisco indicates that the CVE-2026-20127 vulnerability is being actively exploited.

Recommendation

[Update of 26 February 2026] The CERT-FR recommends conducting a compromise search based on the elements documented by Cisco in its security advisory and a blog post [1]: 1. Verification of the legitimacy of control connection peering events: * An example log is provided below. The values associated with `peer-system-ip` and `public-ip` must correspond to expected values based on the information system architecture and SD-WAN configuration. Additionally, the `peer-type` must be consistent with the equipment linked to the `peer-system-ip` address. The timestamp of the event must be associated with maintenance or administration periods. Jul 26 22:03:33 vSmart-01 VDAEMON_0[2571]: %Viptela-vSmart-VDAEMON_0-5-NTCE-1000001: control-connection-state-change new-state:up peer-type:vmanage peer-system-ip:1.1.1.10 public-ip:192.168.3.20 public-port:12345 domain-id:1 site-id:1005 * Additionally, the CERT-FR advises correlating the information present in these events to identify reconnaissance patterns or persistent access attempts. For example, by grouping activities by `peer-type` and `peer-system-ip`. These logs may be present in `/var/log/tmplog/vdebug`, `/var/log/vsyslog`, `/var/log/jsyslog` or `/var/log/messages`. 2. Verification of the addition of an SSH authentication key for `vmanage-admin`: * The `vmanage-admin` account is a legitimate account used by the system. Attackers may have added an SSH key for this account and used it to connect to the equipment. * It is necessary to validate that authentication events related to the use of a public key for the `vmanage-admin` account can be linked to a known and legitimate IP address. These events are notably listed in …

Official document on cert.ssi.gouv.frread by Patcharo 28 Sept 2026 at 20:03 UTCMachine translation of the French text published by CERT-FR; a text whose translation did not pass Patcharo's checks stays in French. Identifiers, versions and links are copied unchanged.

Advisory (AVI)CERTFR-2026-AVI-0210Published 25 Feb 2026

Multiple vulnerabilities in Cisco Catalyst SD-WAN

Remote arbitrary code executionData integrity breachSecurity policy bypassData confidentiality breachPrivilege escalation

Summary

Multiple vulnerabilities have been discovered in Cisco Catalyst SD-WAN. Some of them allow an attacker to cause remote arbitrary code execution, privilege escalation, and a data confidentiality breach. Cisco indicates that the vulnerability CVE-2026-20127 is actively exploited.

Recommendation

Refer to the vendor's security bulletin to obtain patches (see Documentation section).

Official document on cert.ssi.gouv.frread by Patcharo 28 Sept 2026 at 20:04 UTCMachine translation of the French text published by CERT-FR; a text whose translation did not pass Patcharo's checks stays in French. Identifiers, versions and links are copied unchanged.

Timeline

  1. Added to CISA KEV
  2. Published by the source
  3. CISA remediation due date
  4. Source record last modified
  5. EPSS score computed
  6. Last verified by Patcharo

Official sources

References

Cisco · CISA Known Exploited Vulnerabilities · NVD · FIRST EPSS · Cisco Security Advisory cisco-sa-sdwan-rpa-EHchtZk

How Patcharo reads this

Affected and fixed releases come from the vendor's structured statements and are matched against exact versions; CVSS from NVD, exploitation from CISA KEV and the vendor's own advisory, probability from FIRST EPSS. Missing data stays Unknown and never becomes Not affected.

Read the methodologyRead the guide: Cisco Secure Firewall release trains: Threat Defense, Management Center and ASA versions explained