Cyber Resilience

CVE-2026-26080

Published
20 July 2026
Modified
21 July 2026
CVSS Score v3.1 3.7
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS Score 0.0042 34th percentile
Risk Priority 33 floored blend · peak EPSS

Summary

CVE-2026-26080 is a low-severity Unchecked Return Value (CWE-252) vulnerability in Haproxy (inferred from references). Its CVSS base score is 3.7 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 34th 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.

OWASP Top 10 for Web (2025)

A10:2025 Mishandling of Exceptional Conditions

EU & UK References

Vulnerability Data

HAProxy Community Edition 3.2.x through 3.3.x before 3.3.3 can enter a loop or crash because varint is mishandled. HAProxy Enterprise and ALOHA are also affected.

CWE(s)
CWE-252

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 →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
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-2023-37902Shared CWE-252
CVE-2023-40067Shared CWE-252
CVE-2024-39492Shared CWE-252
CVE-2023-6918Shared CWE-252
CVE-2025-55146Shared CWE-252
CVE-2026-0421Shared CWE-252
CVE-2023-26591Shared CWE-252
CVE-2025-29938Shared CWE-252
CVE-2023-50359Shared CWE-252
CVE-2023-47480Shared CWE-252

Affected Assets

Haproxy
—
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and code evaluation can discover instances where return values are ignored.

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

Requiring a documented development process and coding standards can mandate explicit checking of all function return values.

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 mostly match
prevents

Secure SDLC practices directly require checking and handling all function return values to detect error conditions.

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.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development and acceptance can detect missing return-value checks.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates verification of return values to prevent undetected failures.

A.8.26 Application security requirements partial match
prevents

Application security requirements include input/output validation and error handling that covers return-value checks.

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

Secure system architecture and engineering principles require robust error handling and defensive coding practices.

A.8.28 Secure coding partial match
prevents

Secure coding explicitly requires checking return values to avoid CWE-252.

References