Vulnerability-Lookup

GHSA-PMMG-WC48-VJHQ

Vulnerability from github – Published: 2026-07-21 21:32 – Updated: 2026-07-23 15:30

Details

Data::Buffer::Shared versions before 0.05 for Perl create a world-readable mmap backing file and open it without O_NOFOLLOW.

The segment is created in buf_generic.h with open(path, O_RDWR|O_CREAT|O_EXCL, 0666). O_EXCL blocks a pre-seeded file on create, but the mode is 0666, so under the default umask 022 the file is created mode 0644 (world-readable), and O_NOFOLLOW is absent, so a symlink planted at the path is followed when the segment is attached.

A "Shared" segment naturally lives in a shared directory such as /tmp or /dev/shm, where any local user can read the IPC payloads stored in the world-readable segment, and a pre-planted symlink at the path redirects the open to another file.

Severity

6.2 (Medium)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-64613"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-59"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-21T20:17:03Z",
    "severity": "MODERATE"
  },
  "details": "Data::Buffer::Shared versions before 0.05 for Perl create a world-readable mmap backing file and open it without O_NOFOLLOW.\n\nThe segment is created in buf_generic.h with open(path, O_RDWR|O_CREAT|O_EXCL, 0666). O_EXCL blocks a pre-seeded file on create, but the mode is 0666, so under the default umask 022 the file is created mode 0644 (world-readable), and O_NOFOLLOW is absent, so a symlink planted at the path is followed when the segment is attached.\n\nA \"Shared\" segment naturally lives in a shared directory such as /tmp or /dev/shm, where any local user can read the IPC payloads stored in the world-readable segment, and a pre-planted symlink at the path redirects the open to another file.",
  "id": "GHSA-pmmg-wc48-vjhq",
  "modified": "2026-07-23T15:30:35Z",
  "published": "2026-07-21T21:32:41Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64613"
    },
    {
      "type": "WEB",
      "url": "https://metacpan.org/release/EGOR/Data-Buffer-Shared-0.05/changes"
    },
    {
      "type": "WEB",
      "url": "https://metacpan.org/release/EGOR/Data-Buffer-Shared-0.05/diff/EGOR/Data-Buffer-Shared-0.04#buf_generic.h"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-64613 (GCVE-0-2026-64613)

Vulnerability from cvelistv5 – Published: 2026-07-21 19:05 – Updated: 2026-07-23 12:25

Title

Data::Buffer::Shared versions before 0.05 for Perl create a world-readable mmap backing file and open it without O_NOFOLLOW

Summary

Data::Buffer::Shared versions before 0.05 for Perl create a world-readable mmap backing file and open it without O_NOFOLLOW. The segment is created in buf_generic.h with open(path, O_RDWR|O_CREAT|O_EXCL, 0666). O_EXCL blocks a pre-seeded file on create, but the mode is 0666, so under the default umask 022 the file is created mode 0644 (world-readable), and O_NOFOLLOW is absent, so a symlink planted at the path is followed when the segment is attached. A "Shared" segment naturally lives in a shared directory such as /tmp or /dev/shm, where any local user can read the IPC payloads stored in the world-readable segment, and a pre-planted symlink at the path redirects the open to another file.

Severity

6.2 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-07-23 12:24 UTC

CWE

CWE-732 - Incorrect Permission Assignment for Critical Resource
CWE-59 - Improper Link Resolution Before File Access

Assigner

CPANSec redhat root Scorecard

References

2 references

URL	Tags
https://metacpan.org/release/EGOR/Data-Buffer-Sha…
https://metacpan.org/release/EGOR/Data-Buffer-Sha…	release-notes

Impacted products

1 product

Vendor	Product	Version
EGOR	Data::Buffer::Shared	Affected: 0 , < 0.05 (custom)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "LOCAL",
              "availabilityImpact": "NONE",
              "baseScore": 6.2,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-64613",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-23T12:24:05.650789Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-23T12:25:36.375Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "packageName": "Data-Buffer-Shared",
          "product": "Data::Buffer::Shared",
          "programFiles": [
            "buf_generic.h"
          ],
          "repo": "https://github.com/vividsnow/perl5-data-buffer-shared",
          "vendor": "EGOR",
          "versions": [
            {
              "lessThan": "0.05",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Data::Buffer::Shared versions before 0.05 for Perl create a world-readable mmap backing file and open it without O_NOFOLLOW.\n\nThe segment is created in buf_generic.h with open(path, O_RDWR|O_CREAT|O_EXCL, 0666). O_EXCL blocks a pre-seeded file on create, but the mode is 0666, so under the default umask 022 the file is created mode 0644 (world-readable), and O_NOFOLLOW is absent, so a symlink planted at the path is followed when the segment is attached.\n\nA \"Shared\" segment naturally lives in a shared directory such as /tmp or /dev/shm, where any local user can read the IPC payloads stored in the world-readable segment, and a pre-planted symlink at the path redirects the open to another file."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-732",
              "description": "CWE-732 Incorrect Permission Assignment for Critical Resource",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-59",
              "description": "CWE-59 Improper Link Resolution Before File Access",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-21T19:05:49.579Z",
        "orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "shortName": "CPANSec"
      },
      "references": [
        {
          "url": "https://metacpan.org/release/EGOR/Data-Buffer-Shared-0.05/diff/EGOR/Data-Buffer-Shared-0.04#buf_generic.h"
        },
        {
          "tags": [
            "release-notes"
          ],
          "url": "https://metacpan.org/release/EGOR/Data-Buffer-Shared-0.05/changes"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to Data::Buffer::Shared 0.05 or later, which creates the backing file mode 0600 (owner-only) with O_NOFOLLOW."
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "Data::Buffer::Shared versions before 0.05 for Perl create a world-readable mmap backing file and open it without O_NOFOLLOW",
      "workarounds": [
        {
          "lang": "en",
          "value": "For deployments that cannot upgrade to 0.05, set a restrictive umask so the backing file is not world-readable and place it in a directory only the owning user can access."
        }
      ],
      "x_generator": {
        "engine": "cpansec-cna-tool 0.1"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
    "assignerShortName": "CPANSec",
    "cveId": "CVE-2026-64613",
    "datePublished": "2026-07-21T19:05:49.579Z",
    "dateReserved": "2026-07-20T11:30:10.287Z",
    "dateUpdated": "2026-07-23T12:25:36.375Z",
    "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.
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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-PMMG-WC48-VJHQ

CVE-2026-64613 (GCVE-0-2026-64613)

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