CVE-2026-20262
Cisco Catalyst SD-WAN Manager Arbitrary File Write Vulnerability
A vulnerability in the web UI of Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, could allow an authenticated, remote attacker to create a file or overwrite any file on the filesystem of an affected system. This vulnerability exists because the affected software does not properly validate user-supplied input during a file upload process. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected API endpoint of the affected system. A successful exploit could allow the attacker to create or overwrite any file on the underlying operating system. This file could later be used to elevate to root. To exploit this vulnerability, the attacker must have valid credentials with at least a lower-privileged, single-task user account.
Published Updated Sources: NVD, Cisco (CNA), CISA, FIRST EPSS, GitHub, GitHub Security Advisory
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Confirmed
CISA KEV, listed Jun 15, 2026
EPSS
28%
ahead of 98% of scored CVEs
CVSS base
6.5
medium
CISA SSVC assessment
Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.
Exploitation
Active
none · proof-of-concept · active
Automatable
No
can an attacker script all four kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component
Remediation
The vendor's own words where we have them.
Upgrade Cisco Catalyst SD-WAN Manager to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.
CISA required action
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Federal deadline Jun 29, 2026 — passed 55 days ago
First 24 hours
Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.
- Identify exposed assets running affected vendor/product/version combinations.
- Treat as emergency remediation because CISA KEV status is present.
- Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.
Affected scope
Vendor, product and version as the advisories word them.
| Vendor | Product | Versions | Status |
|---|---|---|---|
| Cisco | Cisco Catalyst SD-WAN Manager | 20.1.12 | Vulnerable |
| Cisco | Cisco Catalyst SD-WAN Manager | 19.2.1 | Vulnerable |
| Cisco | Cisco Catalyst SD-WAN Manager | 18.4.4 | Vulnerable |
| Cisco | Cisco Catalyst SD-WAN Manager | 18.4.5 | Vulnerable |
| Cisco | Cisco Catalyst SD-WAN Manager | 20.1.1.1 | Vulnerable |
| Cisco | Cisco Catalyst SD-WAN Manager | 20.1.1 | Vulnerable |
| Cisco | Cisco Catalyst SD-WAN Manager | 19.3.0 | Vulnerable |
| Cisco | Cisco Catalyst SD-WAN Manager | 19.2.2 | Vulnerable |
| Cisco | Cisco Catalyst SD-WAN Manager | 19.2.099 | Vulnerable |
| Cisco | Cisco Catalyst SD-WAN Manager | 18.3.6 | Vulnerable |
| Cisco | Cisco Catalyst SD-WAN Manager | 18.3.7 | Vulnerable |
| Cisco | Cisco Catalyst SD-WAN Manager | 19.2.0 | Vulnerable |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Availability
None
Confidentiality
None
Integrity
High
Scope
Unchanged
Attack Complexity
Low
Attack Vector
Network
Privileges Req
Low
User Interaction
None
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 6.5 | CVSS 3.1 | medium | 2.8 | 3.6 | Cisco (CNA), GHSA |
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Weakness & attack patterns
- CWE-22
Inferred from the weakness class — not observed against this CVE.
CISA KEV details
CISA lists a CVE here once it has evidence of exploitation against real targets.
Listed
Jun 15, 2026
Federal deadline
Jun 29, 2026
passed 55 days ago
Ransomware use
Unknown
CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a date to argue against.
Public exploit
Capability, not use: code existing is a different claim from anyone running it.
Repositories
7
Detection
Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.
- Prioritize edge telemetry for network-reachable Cisco Catalyst SD-WAN Manager.
- Monitor for scanner or exploit-pattern traffic after 7 public PoC repositories were reported.
Timeline
What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.
- 2026
Added · CVSS 3.1 6.5 (AV:N)
Jul 24, 2026 · NVD
Added to CISA KEV catalog
Jun 15, 2026 · CISA
Initial · CVE published
Jun 15, 2026 · NVD
Added · GHSA-p45r-gcc9-fr7f published (medium)
Jun 15, 2026 · GitHub Security Advisory
References
6 on the record
- sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-arbfw-c2rZvQ
Vendor Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20262
US Government Resource
- nvd.nist.gov/vuln/detail/CVE-2026-20262
NVD, Vendor Advisory
- github.com/advisories/GHSA-p45r-gcc9-fr7f
Exploit, Third Party Advisory
- www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
US Government Resource
- www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
US Government Resource
Elsewhere on this site
- Ciscoevery CVE for this vendor
- June 2026what else CISA listed
- Remote Code Execsame class
- CWE-22other pages naming this weakness
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record1
What should defenders know first?
CVE-2026-20262 is Cisco Catalyst SD-WAN Manager Arbitrary File Write Vulnerability, a medium vulnerability affecting Cisco Catalyst SD-WAN Manager from Cisco. The current evidence lists it in CISA KEV, and the exploit status is: Yes: CISA KEV signal present. Public exploit evidence is: 7 public PoC repositories reported; 0 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 6.5 describes technical severity, while EPSS 28% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.