9.3

CVE-2026-116606: Barracuda Networks Email Security Gateway (ESG) Authentication Bypass Using an Alternate Path or Channel Vulnerability

KEV
Undergoing analysis
Published 02-11-2026Last modified 10-11-2026

Vulnerability summary

CVE-2026-116606 is a critical (CVSS 9.3) vulnerability in Barracuda Networks Barracuda Email Security Gateway (ESG). It is known to be exploited: CISA lists it, first on 10-11-2026. EPSS estimates a 1.60% chance of exploitation in the next 30 days, higher than 76% of scored vulnerabilities.

Priority
Act nowlisted as exploited

Listed as exploited by CISA (10-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
9.3/10
010
Critical · v4.0 (CVE.org)
EPSS score
1.60%
0%100%
Low · Change unavailable
KEVExploited in the wildCritical · listed in 1 catalog
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 02-11-2026
    PublishedVulnerability first disclosed.
  2. 10-11-2026
    Added to CISA KEVExploitedBarracuda Networks Email Security Gateway (ESG) Authentication Bypass Using an Alternate Path or Channel Vulnerability
  3. 10-11-2026
    Last modifiedVulnerability information updated.
  4. 13-11-2026
    CISA remediation dueUpcomingApply mitigations per vendor instructions.

Description

An authentication bypass in Barracuda Email Security Gateway versions earlier than 9.4.0.030 allows 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.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

1.60%

Chance of exploitation in the next 30 days

Percentile

76%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

03-11-202610-11-2026

Known exploited

Compare KEV catalogs
CISA KEVListed
Added
10-11-2026
Federal due date
13-11-2026
ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

CISA required action

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. trust.barracuda.com/security/pre-authentication-authorization-bypass-command-injection github.com/mandiant/Vulnerability-Disclosures/blob/master/2026/MNDT-2026-0042.md nvd.nist.gov/vuln/detail/CVE-2026-116606

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Barracuda networks1 product

1 vendor · 1 product

References

3 links