Exploited vulnerability · CISA KEV

Is CVE-2026-116606 exploited? Yes: in CISA KEV since 10 Nov 2026

Gociux · Barracuda Networks Barracuda Email Security Gateway (ESG) · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2026-116606, Barracuda Networks Email Security Gateway (ESG) Authentication Bypass Using an Alternate Path or Channel Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 10 Nov 2026, 8 days after it was published. It affects Barracuda Networks Barracuda Email Security Gateway (ESG), an internet-facing product of the kind attackers use for initial access. If you run it, CISA's required action is: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

What it is

Barracuda Networks Email Security Gateway (ESG) contains an authentication bypass using an alternate path or channel that could allow an unauthenticated remote attacker to invoke a configuration-import function and restore a crafted, compatible backup archive, resulting in unauthorized modification of the appliance’s global configuration. This vulnerability can be chained with CVE-2026-111560.

What to do

1. Check whether you run it. Look for Barracuda Email Security Gateway (ESG) in your asset inventory, including appliances and cloud images. Stack check lists every exploited Barracuda Networks CVE at once.
2. Apply the fix. Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
3. If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 2 Nov 2026.
4. Get told next time. Email alerts when CISA adds a CVE for Barracuda Networks.

References

• trust.barracuda.com/security/pre-authentication-authorization-bypass-command-in
• github.com/mandiant/Vulnerability-Disclosures/blob/master/2026/MNDT-20
• nvd.nist.gov/vuln/detail/CVE-2026-116606

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in November 2026 · Barracuda Networks scorecard · act-now radar.