Vulnerability-Lookup

GHSA-W9V4-7VPF-W2R4

Vulnerability from github – Published: 2026-04-22 03:31 – Updated: 2026-04-22 15:31

Details

The implementation of TIOCNOTTY failed to clear a back-pointer from the structure representing the controlling terminal to the calling process' session. If the invoking process then exits, the terminal structure may end up containing a pointer to freed memory.

A malicious process can abuse the dangling pointer to grant itself root privileges.

Severity

8.4 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-5398"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-416"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-04-22T03:16:01Z",
    "severity": "HIGH"
  },
  "details": "The implementation of TIOCNOTTY failed to clear a back-pointer from the structure representing the controlling terminal to the calling process\u0027 session.  If the invoking process then exits, the terminal structure may end up containing a pointer to freed memory.\n\nA malicious process can abuse the dangling pointer to grant itself root privileges.",
  "id": "GHSA-w9v4-7vpf-w2r4",
  "modified": "2026-04-22T15:31:39Z",
  "published": "2026-04-22T03:31:36Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-5398"
    },
    {
      "type": "WEB",
      "url": "https://security.freebsd.org/advisories/FreeBSD-SA-26:10.tty.asc"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-5398 (GCVE-0-2026-5398)

Vulnerability from cvelistv5 – Published: 2026-04-22 02:23 – Updated: 2026-04-23 03:56

Title

Kernel use-after-free bug in the TIOCNOTTY handler

Summary

Severity

8.4 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-04-22 00:00 UTC

CWE

CWE-416 - Use After Free

Assigner

freebsd mitre root Scorecard

References

1 reference

URL	Tags
https://security.freebsd.org/advisories/FreeBSD-S…	vendor-advisory

Impacted products

1 product

Vendor	Product	Version
FreeBSD	FreeBSD	Affected: 15.0-RELEASE , < p6 (release) Affected: 14.4-RELEASE , < p2 (release) Affected: 14.3-RELEASE , < p11 (release) Affected: 13.5-RELEASE , < p12 (release)

Date Public

2026-04-21 18:00

Credits

Nicholas Carlini using Claude, Anthropic

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "LOCAL",
              "availabilityImpact": "HIGH",
              "baseScore": 8.4,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "HIGH",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-5398",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-22T00:00:00+00:00",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-04-23T03:56:10.203Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unknown",
          "modules": [
            "tty"
          ],
          "product": "FreeBSD",
          "vendor": "FreeBSD",
          "versions": [
            {
              "lessThan": "p6",
              "status": "affected",
              "version": "15.0-RELEASE",
              "versionType": "release"
            },
            {
              "lessThan": "p2",
              "status": "affected",
              "version": "14.4-RELEASE",
              "versionType": "release"
            },
            {
              "lessThan": "p11",
              "status": "affected",
              "version": "14.3-RELEASE",
              "versionType": "release"
            },
            {
              "lessThan": "p12",
              "status": "affected",
              "version": "13.5-RELEASE",
              "versionType": "release"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Nicholas Carlini using Claude, Anthropic"
        }
      ],
      "datePublic": "2026-04-21T18:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "The implementation of TIOCNOTTY failed to clear a back-pointer from the structure representing the controlling terminal to the calling process\u0027 session.  If the invoking process then exits, the terminal structure may end up containing a pointer to freed memory.\n\nA malicious process can abuse the dangling pointer to grant itself root privileges."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-416",
              "description": "CWE-416: Use After Free",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-22T02:23:56.767Z",
        "orgId": "63664ac6-956c-4cba-a5d0-f46076e16109",
        "shortName": "freebsd"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://security.freebsd.org/advisories/FreeBSD-SA-26:10.tty.asc"
        }
      ],
      "title": "Kernel use-after-free bug in the TIOCNOTTY handler"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "63664ac6-956c-4cba-a5d0-f46076e16109",
    "assignerShortName": "freebsd",
    "cveId": "CVE-2026-5398",
    "datePublished": "2026-04-22T02:23:56.767Z",
    "dateReserved": "2026-04-02T01:48:17.131Z",
    "dateUpdated": "2026-04-23T03:56:10.203Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
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Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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GHSA-W9V4-7VPF-W2R4

CVE-2026-5398 (GCVE-0-2026-5398)

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