Cyber Resilience

CVE-2026-76443

Published
14 September 2026
Modified
15 September 2026
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0039 33th percentile
Risk Priority 71 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-76443 is a critical-severity Improper Neutralization (CWE-707) vulnerability in Cisco Secure Email (inferred from references). Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked at the 33th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

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…

more

that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-76443 are related to issues with improper neutralization that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-707.

CWE(s)
CWE-707

Related Threats

MITRE ATT&CK Enterprise Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-46689Shared CWE-707
CVE-2025-66545Shared CWE-707
CVE-2025-24921Shared CWE-707
CVE-2026-20278Shared CWE-707
CVE-2025-26633Shared CWE-707
CVE-2026-4249Shared CWE-707
CVE-2023-42773Shared CWE-707
CVE-2025-27712Shared CWE-707
CVE-2024-43572Shared CWE-707
CVE-2023-45315Shared CWE-707

Affected Assets

Cisco
Secure Email
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 6 hardening rules · 4 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V1.3.9

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation partial match

Developer testing can discover missing or incorrect neutralization logic.

SI-10 Information Input Validation partial match

Input validation directly enforces well-formed data and security properties before processing.

SI-15 Information Output Filtering partial match

Output filtering enforces neutralization properties on data leaving the system.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 partial match
prevents

Secure SDLC practices directly require input/output neutralization and validation to prevent malformed data handling.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates input validation and output encoding that directly prevent improper neutralization.

A.8.26 Application security requirements partial match
prevents

Application security requirements explicitly call for data validation and sanitization controls addressing neutralization weaknesses.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles include canonicalization and safe parsing, mitigating but not fully covering neutralization issues.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly require proper neutralization of inputs and outputs, eliminating CWE-707.

A.8.29 Security testing in development and acceptance partial match
finds

Security testing can detect neutralization flaws but does not itself implement the required controls.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (higher-evidence rows only; rows rated `none` are excluded).

Oracle Linux 9 (1 rule)
  • V-271523 OL 9 must check the GPG signature of locally installed software packages before installation. prevents CWE-707

References