Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessReach ESA/SMA web interface
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DeliverySend request with ../ traversal sequence
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ExploitEscape intended directory scope
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ExecutionRead arbitrary appliance files
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ImpactDisclose configuration and credentials
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V5 - File Handling Relative path traversal prevention
|
| Exploitation Conditions | Requires network reachability to the Cisco Secure Email Gateway (ESA) or Secure Email and Web Manager (SMA) HTTP/management interface running an affected build (12.8.x through 16.x per the EUVD list). The advisory does not disclose the vulnerable endpoint, parameter, or whether authentication is required, so it is not confirmed that exploitation works against a default, unauthenticated configuration - the likely limiting factor is that management interfaces are typically not internet-exposed and may require an authenticated session. Impact is bounded by the traversal being read-oriented (arbitrary file disclosure) rather than a general write/exec primitive. |
| Impact | Signals are internally consistent but point to a lower real-world priority than the 9.8 headline suggests. The vendor CVSS vector (AV:N/AC:L/PR:N/UI:N, C:H/I:H/A:H) claims remote, unauthenticated, low-complexity full-triad compromise, but this is a batch 'internal security review' hardening disclosure (advisory cisco-sa-hardening-esa-dfCrfXkm) with ZERO technical detail - no affected endpoint, parameter, or statement of whether the flaw is pre- or post-authentication. For a CWE-23 path traversal grouped under a pillar CWE, full I:H and A:H are hard to justify from a read-oriented traversal; the impact is most likely confidentiality (arbitrary file read) with limited integrity. SSVC (Exploitation: none, Automatable: yes, Technical Impact: total) and a low EPSS of 0.43% (36th percentile) with no KEV listing and no public POC indicate no observed exploitation and no weaponization to date. Bottom line: a genuine defect worth patching on internet-facing mail appliances, but the 9.8 rating is likely overstated (assessed closer to a high-7 confidentiality issue); treat as important-but-not-emergency absent evidence of an unauthenticated trigger. Key gap to resolve with Cisco: whether exploitation requires authentication (PR:N vs PR:L) and whether write/delete is truly achievable. |
| Exploit ScenarioDerived | An attacker who can reach the ESA/SMA management or web interface sends a crafted request containing directory-traversal sequences (e.g. ../../) in a path or filename parameter to escape the intended directory and read sensitive files such as configuration, credentials, or logs from the appliance. No public proof-of-concept exists and the advisory omits the vulnerable endpoint, so a working exploit would require reverse-engineering the hardening patch. Because the flaw is marked Automatable:yes, a reliable primitive could be scripted once the parameter is identified. |
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Alert meAnalysisAIv1 – Sep 16, 2026
Path traversal vulnerabilities (CWE-23) in Cisco Secure Email Gateway (ESA) and Cisco Secure Email and Web Manager (SMA) allow a remote attacker to break out of an intended directory and read files the application should not expose. Affected builds span the 12.8.x through 16.x release trains listed in the EUVD record (EUVD-2026-77622), including ESA 13.0.5-007, 14.x, 15.0.x, 15.5.x and 16.0.x builds, and corresponding SMA 12.8.1, 13.x, 14.x, 15.x and 16.x builds; Cisco addressed the issues in internal-hardening software releases documented in advisory cisco-sa-hardening-esa-dfCrfXkm. Cisco's advisory carries a 9.8 score, but our assessment is lower (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N) because the advisory does not disclose the vulnerable endpoint or confirm that the flaw is reachable without an authenticated session; exploitation also requires network reachability to a management interface that is normally not internet-exposed. There is no public exploit identified at time of analysis, EPSS is low at 0.43% (36th percentile), and the issue is not in CISA KEV, although CISA SSVC rates it automatable with total technical impact.
RemediationAI
Patch available per vendor advisory: Cisco states that this internal security review produced software hardening releases that address CVE-2026-76440, so the primary action is to upgrade ESA and SMA appliances to the fixed builds specified in Cisco advisory cisco-sa-hardening-esa-dfCrfXkm (https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-esa-dfCrfXkm); the provided data does not enumerate exact patched version strings, so confirm the target build against that advisory rather than assuming any build at or above the listed affected versions is fixed. Until the upgrade can be scheduled, apply compensating controls targeted at the management plane, since the practical exposure is a path traversal reachable through the HTTP/management interface of an affected appliance: block internet-facing access to the ESA/SMA management interface with firewall or edge ACL rules and restrict it to a dedicated administrative subnet, VPN or jump host (trade-off: remote administrators lose direct UI/CLI access and must tunnel in, which can slow incident response); if the interface previously had broad exposure, treat it as potentially compromised and rotate administrative credentials, API keys and any secrets stored on the appliance, because the read-oriented traversal could have exposed configuration material (trade-off: credential rotation causes brief management-plane disruption and may require coordinated updates in downstream integrations such as mail-flow connectors); review ESA/SMA HTTP access logs and audit logs for traversal patterns such as encoded dot-dot-slash sequences in requests to the management interface, and forward them to the SIEM for detection (trade-off: appliance log retention and detail may be limited, so enable remote logging before relying on this); and apply the management-network segmentation and access-control hardening guidance from the advisory while the upgrade is pending. Note that the Cisco score of 9.8 assumes no privileges (PR:N) while our assessment assumes a low-privileged authenticated actor (PR:L), so do not deprioritize the fix entirely, but treat emergency out-of-band change windows as optional for appliances whose management interfaces are already isolated from untrusted networks. There is no public exploit identified at time of analysis, and no vendor-released workaround beyond the hardening release is described in the available data.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 2 packages in euvd
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Technical ContextAI · show details
The defect class is CWE-23, Relative Path Traversal, which Cisco grouped at the pillar level for this advisory, meaning the release bundles several internally discovered path-handling flaws rather than a single named endpoint. Root cause is inadequate canonicalization and validation of attacker-influenced path components (../ sequences, encoded or double-encoded traversal strings, or absolute paths) before the application performs a filesystem operation, allowing a request to resolve outside the intended web or management content directory. The affected code bases are Cisco Secure Email Gateway (ESA, the mail-filtering appliance previously branded Email Security Appliance) and Cisco Secure Email and Web Manager (SMA, the centralized management appliance), confirmed by the CPE entries cpe:2.3:a:cisco:cisco_secure_email:*:*:*:*:*:*:*:* and cpe:2.3:a:cisco:cisco_secure_email_and_web_manager:*:*:*:*:*:*:*:* with wildcard versions. Our assessed vector (PR:L, C:H/I:L/A:N) frames the practical primitive as authenticated arbitrary file disclosure via the HTTP/management interface rather than a general write or code-execution primitive; the path traversal could in principle expose configuration, credential or mail-store material, which is why confidentiality impact remains High, but integrity impact is limited and availability is unaffected in our scoring.
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Path traversal on an appliance web interface is read-oriented (C:H, minor I:L, no A); management access likely needs a session, so PR:L rather than PR:N.
Primary rating from Vendor (cisco).
CVSS VectorVendor: cisco
DescriptionCVE.org
As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Secure Email Gateway and Cisco Secure Email and Web Manager engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities.
The vulnerabilities tracked by CVE-2026-76440 are related to path traversal issues that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-23.
Executive ViewAI
Cisco Secure Email Gateway (ESA) and Cisco Secure Email and Web Manager (SMA) are affected by a directory traversal flaw that could allow an authenticated attacker with management network access to read files outside the application's intended directories. While no public exploit identified at time of analysis and the management interface is normally not internet-exposed, these are security-critical email controls and a successful exploit could expose sensitive configuration or email-handling data. No vendor-released patch identified at time of analysis, so leadership should prioritize exposure reduction and monitoring.
Restrict management interface access to trusted administrative networks; enforce MFA and least privilege; monitor authentication and file-access logs; apply Cisco hardening guidance from cisco-sa-hardening-esa-dfCrfXkm.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Path traversal exploits occur when applications use user-controlled input to construct file system paths without proper validation.
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EUVD-2026-77622
GHSA-rx6x-7px9-ppg5
NVD
CVE.org
EPSS
Vulnrichment
Exploit-DB