Vulnerability Database

357,869

Total vulnerabilities in the database

CVE-2026-45257 — freebsd / freebsd

Write-what-where Condition

The KTLS receive path decrypted each record in place, assuming that the mbufs holding received data were anonymous and safe to modify. This assumption does not hold for data placed on a socket by sendfile(2), which can reference file-backed memory directly through non-anonymous M_EXTPG pages or EXT_SFBUF mbufs. When the sender transmits such data over a loopback connection without enabling KTLS on the transmit side, the file-backed mbufs reach the receiver's decryption path unchanged. Decrypting a record in place then overwrites the backing file's page cache instead of a private copy of the data.

An unprivileged local user who can read a file can overwrite its contents with data of their choosing by sending the file over a loopback connection on which they have enabled KTLS receive. The write modifies the page cache directly, so it bypasses file flags such as schg and is written back to disk. By overwriting a setuid binary or other trusted file, a local user can escalate privileges, potentially gaining full control of the affected system.

  • Published: Jun 26, 2026
  • Updated: Jun 27, 2026
  • CVE: CVE-2026-45257
  • Severity: High
  • Exploit:
  • CISA KEV:

CVSS v3:

  • Severity: High
  • Score: 7.8
  • AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CWEs:

Software From Fixed in
freebsd / freebsd 14.3 14.3.x
freebsd / freebsd 14.3-p1 14.3-p1.x
freebsd / freebsd 14.3-p10 14.3-p10.x
freebsd / freebsd 14.3-p11 14.3-p11.x
freebsd / freebsd 14.3-p12 14.3-p12.x
freebsd / freebsd 14.3-p13 14.3-p13.x
freebsd / freebsd 14.3-p14 14.3-p14.x
freebsd / freebsd 14.3-p2 14.3-p2.x
freebsd / freebsd 14.3-p3 14.3-p3.x
freebsd / freebsd 14.3-p4 14.3-p4.x
freebsd / freebsd 14.3-p5 14.3-p5.x
freebsd / freebsd 14.3-p6 14.3-p6.x
freebsd / freebsd 14.3-p7 14.3-p7.x
freebsd / freebsd 14.3-p8 14.3-p8.x
freebsd / freebsd 14.3-p9 14.3-p9.x
freebsd / freebsd 14.4 14.4.x
freebsd / freebsd 14.4-p1 14.4-p1.x
freebsd / freebsd 14.4-p2 14.4-p2.x
freebsd / freebsd 14.4-p3 14.4-p3.x
freebsd / freebsd 14.4-p4 14.4-p4.x
freebsd / freebsd 14.4-p5 14.4-p5.x
freebsd / freebsd 14.4-rc1 14.4-rc1.x
freebsd / freebsd 15.0 15.0.x
freebsd / freebsd 15.0-p1 15.0-p1.x
freebsd / freebsd 15.0-p2 15.0-p2.x
freebsd / freebsd 15.0-p3 15.0-p3.x
freebsd / freebsd 15.0-p4 15.0-p4.x
freebsd / freebsd 15.0-p5 15.0-p5.x
freebsd / freebsd 15.0-p6 15.0-p6.x
freebsd / freebsd 15.0-p7 15.0-p7.x
freebsd / freebsd 15.0-p8 15.0-p8.x
freebsd / freebsd 15.0-p9 15.0-p9.x
freebsd / freebsd 15.1-rc2 15.1-rc2.x

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.