Cyber Resilience

CVE-2026-49419

Published
19 August 2026
Modified
20 August 2026
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0029 21th percentile
Risk Priority 63 floored blend · peak EPSS

Summary

CVE-2026-49419 is a high-severity Improper Update of Reference Count (CWE-911) vulnerability in Freebsd (inferred from references). Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 21th 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

When the JAIL_AT_DESC flag is specified, kern_jail_set() and kern_jail_get() released the reference to the caller's current prison before looking up the jail descriptor. If the descriptor lookup failed, error-handling paths released the same reference a second time. An unprivileged local…

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user can trigger a prison reference count underflow, which may cause the prison structure to be freed while still in use. When this is done on the jail host, the bug will generally result in an immediate panic. However, if the user is running in a jail, then it may be possible to exploit the bug to elevate privileges.

CWE(s)
CWE-911

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-2024-45783Shared CWE-911
CVE-2023-2019Shared CWE-911
CVE-2026-46316Shared CWE-911
CVE-2026-46099Shared CWE-911
CVE-2023-22394Shared CWE-911
CVE-2024-46972Shared CWE-911
CVE-2026-52943Shared CWE-911
CVE-2026-42534Shared CWE-911
CVE-2023-5633Shared CWE-911
CVE-2024-43102Shared CWE-911

Affected Assets

Freebsd
—
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 analysis directly exercise reference-counted paths and reveal incorrect updates.

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

Documented development standards and tools can mandate safe reference-count patterns and static checks.

SA-8 Security and Privacy Engineering Principles partial match

Engineering principles can require correct resource lifetime and reference management during design and implementation.

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 prevent reference-count coding errors via reviews, static analysis, and testing.

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 can detect reference-count defects before release, providing partial mitigation.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle practices can include reference-counting rules and automated checks that reduce the likelihood of improper updates.

A.8.26 Application security requirements partial match
prevents

Application security requirements can mandate correct resource-lifetime management, indirectly addressing reference-count errors.

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

Secure system architecture principles encourage explicit resource-ownership models that mitigate reference-count misuse.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly prescribe correct increment/decrement patterns, covering most instances of this weakness.

A.8.32 Change management partial match
prevents

Change-management processes may catch reference-count issues introduced by modifications, but do not address the root coding flaw.

References