- 5.4MediumCVSS base score
- 25.8%Exploitation in 30 daysEPSS · top 2.0% of all CVEs
- YesKnown exploitedin CISA's KEV since 20 Apr 2026
- YesPublic exploitsa reference or SSVC says so
Description
A vulnerability in the API of Cisco Catalyst SD-WAN Manager could allow an authenticated, remote attacker to overwrite arbitrary files on the local file system. To exploit this vulnerability, the attacker must have valid read-only credentials with API access on the affected system. This vulnerability is due to improper file handling on the API interface of an affected system. An attacker could exploit this vulnerability by uploading a malicious file on the local file system. A successful exploit could allow the attacker to overwrite arbitrary files on the affected system and gain vmanage user privileges.
Exploited in the wild
CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog as Cisco Catalyst SD-WAN Manager Incorrect Use of Privileged APIs Vulnerability.
- Added
- 20 Apr 2026
- Fix due (US federal)
- 23 Apr 2026
- Used by ransomware
- Not known
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.
ENISA's EU Vulnerability Database lists it as exploited, from CISA's KEV, since 20 Apr 2026.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. CISA's SSVC rates its exploitation: it is being exploited.
Timeline
ID reserved
By cisco
- 5 months later
· 5 months later
Published
- 54 days later
· 54 days later
Added to CISA KEV
Known exploited in the wild
- 1 day later
· 1 day later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| ciscoCNA (assigner) | 3.1 | Medium5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
| NVDNVD · Analyzed | 3.1 | Medium5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
- EPSS (exploitation in 30 days)
- 25.8% · top 2.0% of all CVEs (9 Nov 2026)
- CISA SSVC
- Exploitation: active · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.4.
Affected products
Cisco · Cisco Catalyst SD-WAN Manager
- affected 20.1.12
- affected 19.2.1
- affected 18.4.4
- affected 18.4.5
- affected 20.1.1.1
- affected 20.1.1
- affected 19.3.0
- affected 19.2.2
- affected 19.2.099
- affected 18.3.6
- affected 18.3.7
- affected 19.2.0
- affected 18.3.8
- affected 19.0.0
- affected 19.1.0
- affected 18.4.302
- affected 18.4.303
- affected 19.2.097
- affected 19.2.098
- affected 17.2.10
- affected 18.3.6.1
- affected 19.0.1a
- affected 18.2.0
- affected 18.4.3
- affected 18.4.1
- affected 17.2.8
- affected 18.3.3.1
- affected 18.4.0
- affected 18.3.1
- affected 17.2.6
- affected 17.2.9
- affected 18.3.4
- affected 17.2.5
- affected 18.3.1.1
- affected 18.3.5
- affected 18.4.0.1
- affected 18.3.3
- affected 17.2.7
- affected 17.2.4
- affected 18.3.0
- and 295 more
What to do
Exploitation: The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerabilities that are described in CVE-2026-20133, CVE-2026-20126, and CVE-2026-20129. In March 2026, the Cisco PSIRT became aware of active exploitation of the vulnerabilities that are described in CVE-2026-20128 and CVE-2026-20122 only. The vulnerabilities that are described in the other CVEs in this advisory are not known to have been compromised. Cisco strongly recommends that customers upgrade to a fixed software release to remediate these vulnerabilities.
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- CISA KEV catalog (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-8673 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-20122)Record last updated .