Security

Updated at the time? No sweat. Check those logs, though

Cisco has updated a February security advisory, adding another product to the list of those affected by the maximum-severity CVE-2026-20127.

Switchzilla made a small amendment to the original advisory on Tuesday evening, noting that Cisco Catalyst SD-WAN Validator, formerly vBond, was also among the boxes attackers could pop open.

Readers may remember the fuss over CVE-2026-20127 (10.0) a few months ago. The make-me-admin improper authentication flaw prompted a Five Eyes alert since attackers could essentially gain persistent root access to all vulnerable instances.

In other words, it's a far-from-ideal situation that could could create espionage opportunities, given the prevalence of Cisco's SD-WAN offerings in Western networks.

Cisco said at the time that attackers could exploit CVE-2026-20127 to gain admin rights, access NETCONF, and reconfigure the SD-WAN fabric, before exploiting CVE-2022-20775 (7.8), a path traversal flaw discovered in September 2022, to gain root access.

Cisco Talos, the company's threat intel arm, posited that the bug could have been exploited for as long as three years by the time it was discovered. 

Talos attributed the exploitation activity to a group it tracks as UAT-8616, whose activity dates back to at least 2023, according to its researchers' estimates. No one has formally attributed UAT-8616 to a specific country or group of individuals, but experts say that it is a highly sophisticated outfit that has a history of targeting critical infrastructure sectors.

Ollie Whitehouse, NCSC-UK's CTO, said at the time: "Our new alert makes clear that organizations using Cisco Catalyst SD-WAN products should urgently investigate their exposure to network compromise and hunt for malicious activity, making use of the new threat hunting advice produced with our international partners to identify evidence of compromise.

"UK organizations are strongly advised to report compromises to the NCSC, and to apply vendor updates and hardening guidance as soon as practicable to reduce the risk of exploitation."

The Register asked Cisco for more information, but it did not immediately respond. 

Customers should not have to make any new changes, provided that they upgraded their software to a fixed version across all systems when the advisory was first published in February, not just SD-WAN Controller and SD-WAN Manager.

The update comes weeks after Cisco disclosed another zero-day affecting Catalyst SD-WAN, suggesting that it had been exploited for at least a week at the time.

Tracked as CVE-2026-20245, it marked the sixth SD-WAN flaw disclosed this year, and the second to be exploited as a zero-day in as many months. ®