Cyber Resilience

CVE-2026-84691

Published
23 September 2026
Modified
24 September 2026
CVSS Score v3.1 8.7
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N
EPSS Score 0.0020 9th percentile
Risk Priority 54 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-2026-84691 is a high-severity Use of Externally-Controlled Format String (CWE-134) vulnerability. Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 9th 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 SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

A flaw was found in Red Hat Ansible Automation Platform's automation- controller. The setting that formats the log message emitted for API 4XX errors is an administrator-controlled Python format-string template that is rendered with a live user object as an…

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argument. Because Python string formatting permits attribute and item traversal on its arguments, an administrator can craft a template that walks from the user object into the application settings and reads the Django secret key and the database password. The formatted message is written to a logger that can be forwarded to an external log aggregator, whose destination is also administrator-controlled, allowing the secrets to be sent off the host. An authenticated administrator can thereby obtain the master encryption key used to protect all stored credentials and the database service password, enabling offline decryption of every stored credential, forgery of user sessions, and direct access to the controller database.

CWE(s)
CWE-134

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
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-2026-17136Shared CWE-134
CVE-2023-36640Shared CWE-134
CVE-2023-39238Shared CWE-134
CVE-2024-58366Shared CWE-134
CVE-2026-67244Shared CWE-134
CVE-2023-21497Shared CWE-134
CVE-2024-31837Shared CWE-134
CVE-2023-48221Shared CWE-134
CVE-2025-52666Shared CWE-134
CVE-2025-53591Shared CWE-134

Affected Assets

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation partial match

Developer testing and static analysis can discover format-string vulnerabilities before deployment.

SA-15 Development Process, Standards, and Tools partial match

Secure development standards and tools can mandate use of static format strings or safe formatting APIs.

SI-10 Information Input Validation partial match

Input validation can reject or sanitize externally supplied format strings before they reach formatting functions.

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.

ID.RA-01 partial match
prevents

Vulnerability identification can discover existing format-string flaws but does not prevent their introduction.

PR.PS-06 partial match
prevents

Secure SDLC practices directly prevent external format strings via code review, static analysis, and safe APIs.

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 SDLC mandates input validation and safe API usage that can prevent externally-controlled format strings.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify safe formatting functions and ban uncontrolled format strings.

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

Secure architecture principles discourage dangerous string-handling patterns that lead to format-string issues.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly forbid the use of untrusted format strings and prescribe safe alternatives.

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

Security testing in development can detect format-string vulnerabilities before release.

References