Arbitrary File Overwrite in Cisco Catalyst SD-WAN Manager API
CVE-2026-20122 is an authenticated arbitrary file overwrite vulnerability in the API of Cisco Catalyst SD-WAN Manager. According to Cisco, the issue is caused by improper file handling in the API interface, allowing a remote attacker with valid read-only credentials and API access to upload a malicious file and overwrite arbitrary files on the local filesystem of the affected system. The flaw affects Cisco Catalyst SD-WAN Manager and has been described in reporting as one of several SD-WAN Manager vulnerabilities exploited in 2026. Successful exploitation can result in overwrite of attacker-chosen files and subsequent privilege gain to the vmanage user context.
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Impact, mitigation & remediation
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Impact
What an attacker gets, and what they’ve been doing with it.
Mitigation
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Remediation
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Exploits
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No public exploit code observed for this vulnerability.
Affected products & vendors
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Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
Recent activity
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A Cisco SD-WAN vulnerability mentioned as one of several other vulnerabilities discovered this year.
A Cisco SD-WAN vulnerability listed by the article as having detected exploitation in 2026.
A previously flagged actively exploited Cisco SD-WAN vulnerability referenced for context only.
An arbitrary file overwrite vulnerability in Cisco Catalyst SD-WAN Manager that the article says attackers have been exploiting as a zero- or n-day.
The version that knows your environment.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.