Vulnerability-Lookup

GHSA-FH9H-5G6M-WC43

Vulnerability from github – Published: 2026-09-22 12:30 – Updated: 2026-09-22 12:30

Details

LibreOffice can read CFF fonts, which may be embedded in documents. A stack buffer overflow existed when reading the hints of a glyph. The number of hints was checked against the wrong bound, so a glyph declaring more hints than the array can hold wrote past its end. In fixed versions the hint count is checked against the capacity the array really has.

Severity

5.4 (Medium)


                  
                    CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:P

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{
  "affected": [],
  "aliases": [
    "CVE-2026-63275"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-787"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-22T12:17:13Z",
    "severity": "MODERATE"
  },
  "details": "LibreOffice can read CFF fonts, which may be embedded in documents. A stack buffer overflow existed when reading the hints of a glyph. The number of hints was checked against the wrong bound, so a glyph declaring more hints than the array can hold wrote past its end. In fixed versions the hint count is checked against the capacity the array really has.",
  "id": "GHSA-fh9h-5g6m-wc43",
  "modified": "2026-09-22T12:30:26Z",
  "published": "2026-09-22T12:30:26Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63275"
    },
    {
      "type": "WEB",
      "url": "https://www.libreoffice.org/about-us/security/advisories/cve-2026-63275"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-63275 (GCVE-0-2026-63275)

Vulnerability from cvelistv5 – Published: 2026-09-22 11:10 – Updated: 2026-09-22 12:23

Title

Stack buffer overflow in CFF font hint handling

Summary

Severity

5.4 (Medium)


                        
                          CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:P

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-22 12:23 UTC

CWE

CWE-787 - Out-of-bounds Write

Assigner

Document Fdn.

References

1 reference

URL	Tags
https://www.libreoffice.org/about-us/security/adv…

Impacted products

1 product

Vendor	Product	Version
The Document Foundation	LibreOffice	Affected: 26.2 , < < 26.2.5 (26.2 series)

Date Public

2026-09-21 23:59

Credits

Claude, found by Anthropic using agents to study the security of open-source projects Ada Logics, validating and reporting Caolán McNamara of Collabora Productivity

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-63275",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-22T12:23:12.191155Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-22T12:23:37.244Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unknown",
          "product": "LibreOffice",
          "vendor": "The Document Foundation",
          "versions": [
            {
              "lessThan": "\u003c 26.2.5",
              "status": "affected",
              "version": "26.2",
              "versionType": "26.2 series"
            }
          ]
        }
      ],
      "credits": [
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          "lang": "en",
          "type": "finder",
          "value": "Claude, found by Anthropic using agents to study the security of open-source projects"
        },
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          "type": "analyst",
          "value": "Ada Logics, validating and reporting"
        },
        {
          "lang": "en",
          "type": "remediation developer",
          "value": "Caol\u00e1n McNamara of Collabora Productivity"
        }
      ],
      "datePublic": "2026-09-21T23:59:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
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              "base64": false,
              "type": "text/html",
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            }
          ],
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        }
      ],
      "impacts": [
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          "capecId": "CAPEC-44",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-44 Overflow Binary Resource File"
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        }
      ],
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            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "LOCAL",
            "baseScore": 5.4,
            "baseSeverity": "MEDIUM",
            "exploitMaturity": "PROOF_OF_CONCEPT",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "valueDensity": "NOT_DEFINED",
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            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "LOW",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
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          "scenarios": [
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              "lang": "en",
              "value": "GENERAL"
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      "problemTypes": [
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          "descriptions": [
            {
              "cweId": "CWE-787",
              "description": "CWE-787 Out-of-bounds Write",
              "lang": "en",
              "type": "CWE"
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      "providerMetadata": {
        "dateUpdated": "2026-09-22T11:10:26.876Z",
        "orgId": "4fe7d05b-1353-44cc-8b7a-1e416936dff2",
        "shortName": "Document Fdn."
      },
      "references": [
        {
          "url": "https://www.libreoffice.org/about-us/security/advisories/cve-2026-63275"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "Stack buffer overflow in CFF font hint handling",
      "x_generator": {
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  },
  "cveMetadata": {
    "assignerOrgId": "4fe7d05b-1353-44cc-8b7a-1e416936dff2",
    "assignerShortName": "Document Fdn.",
    "cveId": "CVE-2026-63275",
    "datePublished": "2026-09-22T11:10:26.876Z",
    "dateReserved": "2026-07-16T08:17:05.512Z",
    "dateUpdated": "2026-09-22T12:23:37.244Z",
    "state": "PUBLISHED"
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  "dataType": "CVE_RECORD",
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}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
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.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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GHSA-FH9H-5G6M-WC43

CVE-2026-63275 (GCVE-0-2026-63275)

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