What is CVE-2026-20262?
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.
The record classifies CVE-2026-20262 under weakness class CWE-22. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction, and has high impact on integrity. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 135 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 6.5 — MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - EPSS (FIRST)
- 28.1% probability of exploitation in the next 30 days, higher than 98.0% of all scored CVEs
- CISA KEV
- Listed since 2026-06-15, federal remediation deadline 2026-06-29
- Threadlinqs priority
- 9/10 — CISA KEV-listed, which Threadlinqs floors at 9
- Published
- 2026-06-15, last modified 2026-06-17
Is CVE-2026-20262 being exploited?
CISA added CVE-2026-20262 to the Known Exploited Vulnerabilities catalog on 2026-06-15, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2026-06-29 under BOD 22-01. Weaponised exploit code for CVE-2026-20262 is publicly available. 2 public proof-of-concept repositories are tracked for this identifier. It currently carries a trending score of 48 in the Threadlinqs vulnerability feed.
Affected products and versions
- Cisco: Catalyst SD-WAN Manager
How to fix CVE-2026-20262
Because CVE-2026-20262 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2026-06-29. No vendor patch reference has been recorded for CVE-2026-20262 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-20262
1 tracked threat in the Threadlinqs corpus references CVE-2026-20262, either in the campaign’s CVE list or as an indicator on the campaign record.
Sources
Enriched from CVE.org, FIRST EPSS, CISA KEV, GitHub Security Advisories, public proof-of-concept repositories. Last verified by Threadlinqs on .