Vulnerability-Lookup

UBUNTU-CVE-2026-40492 (CVE-2026-40492)

Vulnerability from osv_ubuntu – Published: 2026-04-18 03:16 – Updated: 2026-05-20 15:27 – Source website

Details

SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to commit 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02, the XWD codec resolves pixel format based on pixmap_depth but the byte-swap code uses bits_per_pixel independently. When pixmap_depth=8 (BPP8_INDEXED, 1 byte/pixel buffer) but bits_per_pixel=32, the byte-swap loop accesses memory as uint32_t*, reading/writing 4x the allocated buffer size. This is a different vulnerability from the previously reported GHSA-3g38-x2pj-mv55 (CVE-2026-27168), which addressed bytes_per_line validation. Commit 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02 contains a patch.

Severity

9.8 (Critical)


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

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-40492	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-40492	REPORT
	https://github.com/HappySeaFox/sail/security/advi…	REPORT

JSON

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{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libsail-c++0t64",
            "binary_version": "0.9.0+repack-2.1build1"
          },
          {
            "binary_name": "libsail-common0t64",
            "binary_version": "0.9.0+repack-2.1build1"
          },
          {
            "binary_name": "libsail-manip0t64",
            "binary_version": "0.9.0+repack-2.1build1"
          },
          {
            "binary_name": "libsail0t64",
            "binary_version": "0.9.0+repack-2.1build1"
          },
          {
            "binary_name": "sail-codecs",
            "binary_version": "0.9.0+repack-2.1build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "sail",
        "purl": "pkg:deb/ubuntu/sail@0.9.0+repack-2.1build1?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.9.0+repack-1",
        "0.9.0+repack-2",
        "0.9.0+repack-2.1",
        "0.9.0+repack-2.1build1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libsail-c++0t64",
            "binary_version": "0.9.9-1"
          },
          {
            "binary_name": "libsail-common0t64",
            "binary_version": "0.9.9-1"
          },
          {
            "binary_name": "libsail-manip0t64",
            "binary_version": "0.9.9-1"
          },
          {
            "binary_name": "libsail0t64",
            "binary_version": "0.9.9-1"
          },
          {
            "binary_name": "sail-codecs",
            "binary_version": "0.9.9-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "sail",
        "purl": "pkg:deb/ubuntu/sail@0.9.9-1?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.9.7-1build1",
        "0.9.8-1",
        "0.9.9-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libsail-c++0t64",
            "binary_version": "0.9.10-1"
          },
          {
            "binary_name": "libsail-common0t64",
            "binary_version": "0.9.10-1"
          },
          {
            "binary_name": "libsail-manip0t64",
            "binary_version": "0.9.10-1"
          },
          {
            "binary_name": "libsail0t64",
            "binary_version": "0.9.10-1"
          },
          {
            "binary_name": "sail-codecs",
            "binary_version": "0.9.10-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "sail",
        "purl": "pkg:deb/ubuntu/sail@0.9.10-1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.9.9-1",
        "0.9.10-1"
      ]
    }
  ],
  "aliases": [],
  "details": "SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to commit 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02, the XWD codec resolves pixel format based on `pixmap_depth` but the byte-swap code uses `bits_per_pixel` independently. When `pixmap_depth=8` (BPP8_INDEXED, 1 byte/pixel buffer) but `bits_per_pixel=32`, the byte-swap loop accesses memory as `uint32_t*`, reading/writing 4x the allocated buffer size. This is a different vulnerability from the previously reported GHSA-3g38-x2pj-mv55 (CVE-2026-27168), which addressed `bytes_per_line` validation. Commit 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02 contains a patch.",
  "id": "UBUNTU-CVE-2026-40492",
  "modified": "2026-05-20T15:27:26Z",
  "published": "2026-04-18T03:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-40492"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-40492"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/HappySeaFox/sail/security/advisories/GHSA-526v-vm72-4v64"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-40492"
  ]
}

CVE-2026-40492 (GCVE-0-2026-40492)

Vulnerability from cvelistv5 – Published: 2026-04-18 01:39 – Updated: 2026-04-20 15:24

Title

SAIL has heap buffer overflow in XWD decoder — bits_per_pixel vs pixmap_depth type confusion in byte-swap

Summary

SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to commit 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02, the XWD codec resolves pixel format based on `pixmap_depth` but the byte-swap code uses `bits_per_pixel` independently. When `pixmap_depth=8` (BPP8_INDEXED, 1 byte/pixel buffer) but `bits_per_pixel=32`, the byte-swap loop accesses memory as `uint32_t*`, reading/writing 4x the allocated buffer size. This is a different vulnerability from the previously reported GHSA-3g38-x2pj-mv55 (CVE-2026-27168), which addressed `bytes_per_line` validation. Commit 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02 contains a patch.

Severity

9.8 (Critical)


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

SSVC

Exploitation: poc Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-04-20 15:24 UTC

CWE

CWE-787 - Out-of-bounds Write

Assigner

GitHub_M mitre root

References

2 references

URL	Tags
https://github.com/HappySeaFox/sail/security/advi…	x_refsource_CONFIRM
https://github.com/HappySeaFox/sail/commit/36aa5c…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
HappySeaFox	sail	Affected: < 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-40492",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-20T15:24:38.837811Z",
                "version": "2.0.3"
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          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
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        "references": [
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            "tags": [
              "exploit"
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            "url": "https://github.com/HappySeaFox/sail/security/advisories/GHSA-526v-vm72-4v64"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "sail",
          "vendor": "HappySeaFox",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to commit 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02, the XWD codec resolves pixel format based on `pixmap_depth` but the byte-swap code uses `bits_per_pixel` independently. When `pixmap_depth=8` (BPP8_INDEXED, 1 byte/pixel buffer) but `bits_per_pixel=32`, the byte-swap loop accesses memory as `uint32_t*`, reading/writing 4x the allocated buffer size. This is a different vulnerability from the previously reported GHSA-3g38-x2pj-mv55 (CVE-2026-27168), which addressed `bytes_per_line` validation. Commit 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02 contains a patch."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          }
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      ],
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          "descriptions": [
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              "cweId": "CWE-787",
              "description": "CWE-787: Out-of-bounds Write",
              "lang": "en",
              "type": "CWE"
            }
          ]
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      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-18T01:39:48.056Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/HappySeaFox/sail/security/advisories/GHSA-526v-vm72-4v64",
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        },
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          "tags": [
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          "url": "https://github.com/HappySeaFox/sail/commit/36aa5c7ec8a2bb35f6fb867a1177a6f141156b02"
        }
      ],
      "source": {
        "advisory": "GHSA-526v-vm72-4v64",
        "discovery": "UNKNOWN"
      },
      "title": "SAIL has heap buffer overflow in XWD decoder \u2014 bits_per_pixel vs pixmap_depth type confusion in byte-swap"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
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    "datePublished": "2026-04-18T01:39:48.056Z",
    "dateReserved": "2026-04-13T19:50:42.115Z",
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    "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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.