Cyber Resilience

CVE-2026-77406

Published
16 September 2026
Modified
23 September 2026
CVSS Score v4 8.2
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0041 35th percentile
Risk Priority 43 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-2026-77406 is a high-severity Signed to Unsigned Conversion Error (CWE-195) vulnerability. Its CVSS base score is 8.2 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 35th 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

RabbitMQ amqp091-go is a Go AMQP 0.9.1 client. Prior to 1.13.0, Channel.Qos in channel.go accepts negative prefetchCount and prefetchSize integers and casts them directly to uint16 and uint32 fields in the basic.qos method because validateQos is absent. Values such as…

more

-1 therefore wrap to 65535 or 4294967295 instead of being rejected. An application that permits untrusted configuration of these Qos values can unintentionally request extremely large prefetch limits, allowing a broker to deliver enough queued messages to exhaust client memory and disrupt processing. This issue is fixed in version 1.13.0.

CWE(s)
CWE-195

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-2025-65495Shared CWE-195
CVE-2025-67897Shared CWE-195
CVE-2026-26981Shared CWE-195
CVE-2026-85441Shared CWE-195
CVE-2025-24792Shared CWE-195
CVE-2026-55991Shared CWE-195
CVE-2025-30646Shared CWE-195
CVE-2024-25388Shared CWE-195
CVE-2023-28063Shared CWE-195
CVE-2023-3635Shared CWE-195

Affected Assets

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation partial match

Developer testing and evaluation can discover conversion errors through static analysis, fuzzing, or targeted unit tests.

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

Requiring documented development standards and tools can enforce coding rules that prohibit or safely wrap such casts.

SA-8 Security and Privacy Engineering Principles partial match

Engineering principles can mandate safe integer handling and strong typing to avoid unsafe signed-to-unsigned casts.

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 (static analysis, code review, safe-integer standards) directly prevent signed-to-unsigned conversion errors.

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 practices that can catch signed-to-unsigned conversion errors during design and coding.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify safe integer handling and type-conversion rules.

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

Secure system architecture and engineering principles include data-type safety and overflow prevention.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly prohibit unsafe signed-to-unsigned casts and require defensive checks.

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

Security testing in development can detect conversion-related defects before release.

References