Vulnerability-Lookup

GHSA-W4Q3-279C-XVRV

Vulnerability from github – Published: 2026-08-26 21:31 – Updated: 2026-08-26 21:31

Details

A heap-based buffer overflow vulnerability exists in the Dia diagram editor WPG file format importer.

In plug-ins/wpg/wpg-import.c, the WPG import renderer allocates a fixed palette with:

ren->pPal = g_new0(WPGColorRGB, 256);

When handling a WPG_COLORMAP record, the parser reads a start index (i16) and number of colors (iNum16) from the file and reads palette data with:

bRet &= (iNum16 == (int)fread(&ren->pPal[i16], sizeof(WPGColorRGB), iNum16, f));

The only bounds-related check is if (i16 >= 0 && i16 <= iSize), where iSize is the WPG record size—not the palette capacity. There is no validation that i16 is less than 256 or that i16 + iNum16 does not exceed 256.

A malicious WPG file can supply i16=256 and iNum16=264. That causes fread() to write 792 bytes starting at &pPal[256], while the palette buffer is only 768 bytes (256 entries × 3 bytes). This overflows into adjacent heap metadata and can crash Dia (SIGABRT / malloc corruption errors) or, depending on heap layout and exploit primitives, potentially lead to arbitrary code execution.

Exploitation requires convincing a user to open a crafted WPG file via Dia's file dialog, command line, or file association. No special privileges are required to deliver the file to the victim.

Affected component: WPG parser (plug-ins/wpg/wpg-import.c). Affected versions: all Dia versions containing this code path (reporter tested Dia 0.98+git20260221-1; issue present on upstream master as of 2026-08-21).

Severity

7.8 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-77652"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-122"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-26T20:18:02Z",
    "severity": "HIGH"
  },
  "details": "A heap-based buffer overflow vulnerability exists in the Dia diagram editor WPG file format importer.\n\nIn plug-ins/wpg/wpg-import.c, the WPG import renderer allocates a fixed palette with:\n\n    ren-\u003epPal = g_new0(WPGColorRGB, 256);\n\nWhen handling a WPG_COLORMAP record, the parser reads a start index (i16) and number of colors (iNum16) from the file and reads palette data with:\n\n    bRet \u0026= (iNum16 == (int)fread(\u0026ren-\u003epPal[i16], sizeof(WPGColorRGB), iNum16, f));\n\nThe only bounds-related check is `if (i16 \u003e= 0 \u0026\u0026 i16 \u003c= iSize)`, where iSize is the WPG record size\u2014not the palette capacity. There is no validation that i16 is less than 256 or that i16 + iNum16 does not exceed 256.\n\nA malicious WPG file can supply i16=256 and iNum16=264. That causes fread() to write 792 bytes starting at \u0026pPal[256], while the palette buffer is only 768 bytes (256 entries \u00d7 3 bytes). This overflows into adjacent heap metadata and can crash Dia (SIGABRT / malloc corruption errors) or, depending on heap layout and exploit primitives, potentially lead to arbitrary code execution.\n\nExploitation requires convincing a user to open a crafted WPG file via Dia\u0027s file dialog, command line, or file association. No special privileges are required to deliver the file to the victim.\n\nAffected component: WPG parser (plug-ins/wpg/wpg-import.c).\nAffected versions: all Dia versions containing this code path (reporter tested Dia 0.98+git20260221-1; issue present on upstream master as of 2026-08-21).",
  "id": "GHSA-w4q3-279c-xvrv",
  "modified": "2026-08-26T21:31:45Z",
  "published": "2026-08-26T21:31:45Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-77652"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2026-77652"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2520884"
    },
    {
      "type": "WEB",
      "url": "https://gitlab.gnome.org/GNOME/dia/-/blob/master/plug-ins/wpg/wpg-import.c"
    },
    {
      "type": "WEB",
      "url": "https://gitlab.gnome.org/GNOME/dia/-/issues/580"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-77652 (GCVE-0-2026-77652)

Vulnerability from cvelistv5 – Published: 2026-08-26 19:21 – Updated: 2026-08-26 19:21

Title

Dia: dia: heap buffer overflow in wpg colormap parser via out-of-bounds palette index

Summary

A heap-based buffer overflow vulnerability exists in the Dia diagram editor WPG file format importer. In plug-ins/wpg/wpg-import.c, the WPG import renderer allocates a fixed palette with: ren->pPal = g_new0(WPGColorRGB, 256); When handling a WPG_COLORMAP record, the parser reads a start index (i16) and number of colors (iNum16) from the file and reads palette data with: bRet &= (iNum16 == (int)fread(&ren->pPal[i16], sizeof(WPGColorRGB), iNum16, f)); The only bounds-related check is `if (i16 >= 0 && i16 <= iSize)`, where iSize is the WPG record size—not the palette capacity. There is no validation that i16 is less than 256 or that i16 + iNum16 does not exceed 256. A malicious WPG file can supply i16=256 and iNum16=264. That causes fread() to write 792 bytes starting at &pPal[256], while the palette buffer is only 768 bytes (256 entries × 3 bytes). This overflows into adjacent heap metadata and can crash Dia (SIGABRT / malloc corruption errors) or, depending on heap layout and exploit primitives, potentially lead to arbitrary code execution. Exploitation requires convincing a user to open a crafted WPG file via Dia's file dialog, command line, or file association. No special privileges are required to deliver the file to the victim. Affected component: WPG parser (plug-ins/wpg/wpg-import.c). Affected versions: all Dia versions containing this code path (reporter tested Dia 0.98+git20260221-1; issue present on upstream master as of 2026-08-21).

Severity

7.8 (High)


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

CWE

CWE-122 - Heap-based Buffer Overflow

Assigner

fedora redhat root

References

4 references

URL	Tags
https://access.redhat.com/security/cve/CVE-2026-77652	vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2520884	issue-trackingx_refsource_REDHAT
https://gitlab.gnome.org/GNOME/dia/-/blob/master/…
https://gitlab.gnome.org/GNOME/dia/-/issues/580

Impacted products

1 product

Vendor	Product	Version
GNOME	Dia	Affected: 0 , ≤ 0.98+git20260221-1 (semver)

Date Public

2026-08-21 00:00

Credits

Red Hat would like to thank Robin "drzobin" Larsson for reporting this issue.

Show details on NVD website

JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "collectionURL": "https://gitlab.gnome.org/GNOME/dia/-/issues/580",
          "defaultStatus": "unaffected",
          "packageName": "dia",
          "product": "Dia",
          "vendor": "GNOME",
          "versions": [
            {
              "lessThanOrEqual": "0.98+git20260221-1",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Red Hat would like to thank Robin \"drzobin\" Larsson for reporting this issue."
        }
      ],
      "datePublic": "2026-08-21T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "A heap-based buffer overflow vulnerability exists in the Dia diagram editor WPG file format importer.\n\nIn plug-ins/wpg/wpg-import.c, the WPG import renderer allocates a fixed palette with:\n\n    ren-\u003epPal = g_new0(WPGColorRGB, 256);\n\nWhen handling a WPG_COLORMAP record, the parser reads a start index (i16) and number of colors (iNum16) from the file and reads palette data with:\n\n    bRet \u0026= (iNum16 == (int)fread(\u0026ren-\u003epPal[i16], sizeof(WPGColorRGB), iNum16, f));\n\nThe only bounds-related check is `if (i16 \u003e= 0 \u0026\u0026 i16 \u003c= iSize)`, where iSize is the WPG record size\u2014not the palette capacity. There is no validation that i16 is less than 256 or that i16 + iNum16 does not exceed 256.\n\nA malicious WPG file can supply i16=256 and iNum16=264. That causes fread() to write 792 bytes starting at \u0026pPal[256], while the palette buffer is only 768 bytes (256 entries \u00d7 3 bytes). This overflows into adjacent heap metadata and can crash Dia (SIGABRT / malloc corruption errors) or, depending on heap layout and exploit primitives, potentially lead to arbitrary code execution.\n\nExploitation requires convincing a user to open a crafted WPG file via Dia\u0027s file dialog, command line, or file association. No special privileges are required to deliver the file to the victim.\n\nAffected component: WPG parser (plug-ins/wpg/wpg-import.c).\nAffected versions: all Dia versions containing this code path (reporter tested Dia 0.98+git20260221-1; issue present on upstream master as of 2026-08-21)."
        }
      ],
      "metrics": [
        {
          "other": {
            "content": {
              "namespace": "https://access.redhat.com/security/updates/classification/",
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            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
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          "descriptions": [
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              "description": "Heap-based Buffer Overflow",
              "lang": "en",
              "type": "CWE"
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        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-26T19:21:39.936Z",
        "orgId": "92fb86c3-55a5-4fb5-9c3f-4757b9e96dc5",
        "shortName": "fedora"
      },
      "references": [
        {
          "tags": [
            "vdb-entry",
            "x_refsource_REDHAT"
          ],
          "url": "https://access.redhat.com/security/cve/CVE-2026-77652"
        },
        {
          "name": "RHBZ#2520884",
          "tags": [
            "issue-tracking",
            "x_refsource_REDHAT"
          ],
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2520884"
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          "time": "2026-08-21T03:45:55.032Z",
          "value": "Reported to Red Hat."
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          "lang": "en",
          "time": "2026-08-21T00:00:00.000Z",
          "value": "Made public."
        }
      ],
      "title": "Dia: dia: heap buffer overflow in wpg colormap parser via out-of-bounds palette index",
      "x_generator": {
        "engine": "cvelib 1.8.0"
      },
      "x_redhatCweChain": "CWE-122: Heap-based Buffer Overflow"
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  "cveMetadata": {
    "assignerOrgId": "92fb86c3-55a5-4fb5-9c3f-4757b9e96dc5",
    "assignerShortName": "fedora",
    "cveId": "CVE-2026-77652",
    "datePublished": "2026-08-26T19:21:39.936Z",
    "dateReserved": "2026-08-21T04:00:13.905Z",
    "dateUpdated": "2026-08-26T19:21:39.936Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Detection rules are retrieved from Rulezet.

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.

Action not permitted

GHSA-W4Q3-279C-XVRV

CVE-2026-77652 (GCVE-0-2026-77652)

Tags

Sightings

Nomenclature