Cisco SD-WAN: file access flaw under attack

What is affected

Cisco SD-WAN is mostly run by companies, schools and public bodies, not on home computers. You are unlikely to have it yourself, but organisations that hold your data may. Breaches that start with flaws like this one are how personal data ends up leaked.

Cisco SD-WAN CLI contains a path traversal vulnerability that could allow an authenticated local attacker to gain elevated privileges via improper access controls on commands within the application CLI. A successful exploit could allow the attacker to execute arbitrary commands as the root user.

What an attacker can do

This is a file access flaw. It lets an attacker read or write files they should never reach, such as configuration files that hold passwords, or upload a malicious file that the system then runs.

How it is reached

Needs access to the device or a file opened on it

Access the attacker needs

A basic user account

Does the victim have to do something?

No, works without the victim doing anything

What to do

1. At home: nothing to install. Keep your own devices updated and use a different password for every service, so that a breach at one organisation does not open your other accounts.
2. If you administer Cisco SD-WAN at work: apply the vendor's fix or mitigation now and review logs for signs of compromise, because the flaw was being exploited before it was listed.
3. If the product is past its support date and no fix exists, take it off the internet or retire it.

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.

Vendor advisories and fixes

• cisco.comwww.cisco.com/c/en/us/support/docs/csa/cisco-sa-sd-wan-priv-E6e8tEdF.html

How urgent is it

CISA added this vulnerability to its Known Exploited Vulnerabilities catalogue on February 25, 2026, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by February 27, 2026, a deadline that has already passed. That deadline does not bind anyone else, but it shows how seriously the agency rates it.

The EPSS model estimates a 12% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 96% of all scored vulnerabilities.

Its CVSS severity score is 7.8 out of 10 (high), as recorded in the US National Vulnerability Database.

Technical description

A vulnerability in the CLI of Cisco SD-WAN Software could allow an authenticated, local attacker to gain elevated privileges. This vulnerability is due to improper access controls on commands within the application CLI. An attacker could exploit this vulnerability by running a maliciously crafted command on the application CLI. A successful exploit could allow the attacker to execute arbitrary commands as the root user. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sd-wan-priv-E6e8tEdF