ALSA-2026:0443 (CVE-2025-39993)

Vulnerability from osv_almalinux – Published: 2026-01-12 00:00 – Updated: 2026-01-16 15:37 – Source website
VLAI
Summary
Important: kernel-rt security update
Details

The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements.

Security Fix(es):

  • kernel: media: rc: fix races with imon_disconnect() (CVE-2025-39993)
  • kernel: sctp: avoid NULL dereference when chunk data buffer is missing (CVE-2025-40240)
  • kernel: libceph: fix potential use-after-free in have_mon_and_osd_map() (CVE-2025-68285)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

References
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "kernel-rt"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.18.0-553.92.1.rt7.433.el8_10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "kernel-rt-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.18.0-553.92.1.rt7.433.el8_10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "kernel-rt-debug"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.18.0-553.92.1.rt7.433.el8_10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "kernel-rt-debug-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.18.0-553.92.1.rt7.433.el8_10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "kernel-rt-debug-devel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.18.0-553.92.1.rt7.433.el8_10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "kernel-rt-debug-modules"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.18.0-553.92.1.rt7.433.el8_10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "kernel-rt-debug-modules-extra"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.18.0-553.92.1.rt7.433.el8_10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "kernel-rt-devel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.18.0-553.92.1.rt7.433.el8_10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "kernel-rt-modules"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.18.0-553.92.1.rt7.433.el8_10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "kernel-rt-modules-extra"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.18.0-553.92.1.rt7.433.el8_10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements.  \n\nSecurity Fix(es):  \n\n  * kernel: media: rc: fix races with imon_disconnect() (CVE-2025-39993)\n  * kernel: sctp: avoid NULL dereference when chunk data buffer is missing (CVE-2025-40240)\n  * kernel: libceph: fix potential use-after-free in have_mon_and_osd_map() (CVE-2025-68285)\n\n\nFor more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.\n",
  "id": "ALSA-2026:0443",
  "modified": "2026-01-16T15:37:02Z",
  "published": "2026-01-12T00:00:00Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://access.redhat.com/errata/RHSA-2026:0443"
    },
    {
      "type": "REPORT",
      "url": "https://access.redhat.com/security/cve/CVE-2025-39993"
    },
    {
      "type": "REPORT",
      "url": "https://access.redhat.com/security/cve/CVE-2025-40240"
    },
    {
      "type": "REPORT",
      "url": "https://access.redhat.com/security/cve/CVE-2025-68285"
    },
    {
      "type": "REPORT",
      "url": "https://bugzilla.redhat.com/2404121"
    },
    {
      "type": "REPORT",
      "url": "https://bugzilla.redhat.com/2418832"
    },
    {
      "type": "REPORT",
      "url": "https://bugzilla.redhat.com/2422801"
    },
    {
      "type": "ADVISORY",
      "url": "https://errata.almalinux.org/8/ALSA-2026-0443.html"
    }
  ],
  "related": [
    "CVE-2025-39993",
    "CVE-2025-40240",
    "CVE-2025-68285"
  ],
  "schema_version": "1.7.0",
  "summary": "Important: kernel-rt security update",
  "upstream": [
    "CVE-2025-39993",
    "CVE-2025-40240",
    "CVE-2025-68285"
  ]
}



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