Arbitrary File Overwrite in Cisco Catalyst SD-WAN Manager API
CVE-2026-20122 is a vulnerability in the API of Cisco Catalyst SD-WAN Manager that allows an authenticated remote attacker to overwrite arbitrary files on the local filesystem. According to the provided Cisco description, the issue is caused by improper file handling in the API interface of an affected system. An attacker with valid read-only credentials and API access can upload a malicious file and cause arbitrary file overwrite on the target appliance. Successful exploitation can result in privilege escalation to vManage user privileges. The provided context also notes this flaw has been observed in the wild and has been chained with other Cisco Catalyst SD-WAN Manager vulnerabilities, including CVE-2026-20128 and CVE-2026-20133, to obtain broader unauthorized access.
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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
Patch, then assume compromise.
Exploits
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Affected products & vendors
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
Recent activity
83 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A Cisco Catalyst SD-WAN-related flaw that Cisco warned was being abused in the wild.
An authentication bypass vulnerability affecting Cisco Catalyst SD-WAN, observed in active network exploitation attempts.
One of three vulnerabilities in unpatched Cisco Catalyst SD-WAN Infrastructure that were chained together in widespread in-the-wild active exploitation.
A previously reported Cisco Catalyst SD-WAN vulnerability that Cisco says continues to be exploited.
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.