CVE-2026-39457 (High) detected in src4.0.4

[mend-bolt-for-github]

CVE-2026-39457 - High Severity Vulnerability

Vulnerable Library - src4.0.4

Library home page: https://github.com/MidnightBSD/src.git

Found in base branch: stable/4.0

Vulnerable Source Files (1)

/lib/libnv/msgio.c

Vulnerability Details

When exchanging data over a socket, libnv uses select(2) to wait for data to arrive. However, it does not verify whether the provided socket descriptor fits in select(2)'s file descriptor set size limit of FD_SETSIZE (1024).
An attacker who is able to force a libnv application to allocate large file descriptors, e.g., by opening many descriptors and executing a program which is not careful to close them upon startup, can trigger stack corruption. If the target application is setuid-root, then this could be used to elevate local privileges.

Publish Date: 2026-04-30

URL: CVE-2026-39457

CVSS 3 Score Details (7.8)

Base Score Metrics:

• Exploitability Metrics:
  • Attack Vector: Local
  • Attack Complexity: Low
  • Privileges Required: Low
  • User Interaction: None
  • Scope: Unchanged
• Impact Metrics:
  • Confidentiality Impact: High
  • Integrity Impact: High
  • Availability Impact: High

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Release Date: 2026-04-30

Fix Resolution: https://github.com/freebsd/freebsd-src.git - release/15.0.0-p7,https://github.com/freebsd/freebsd-src.git - release/14.4.0-p3,https://github.com/freebsd/freebsd-src.git - release/13.5.0-p13,https://github.com/freebsd/freebsd-src.git - release/14.3.0-p12

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