FKIE_CVE-2026-44638

Vulnerability from fkie_nvd - Published: 2026-05-14 20:17 - Updated: 2026-05-15 17:54
Severity
2.5 (Low) - CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L
2.5 (Low) - CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L
Summary
libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. From to 1.8.7-r1, a wrong NULL check after an allocation call in sixel_decode_raw and sixel_decode causes a NULL pointer dereference whenever the allocation fails. The check tests the address of the output parameter (always non-NULL) instead of the value the malloc returned. On allocation failure, the function continues and writes through a NULL pointer, crashing the process. This is a denial of service against any caller of these public APIs that hits a low-memory condition. This vulnerability is fixed in 1.8.7-r2.
References
security-advisories@github.comhttps://github.com/saitoha/libsixel/security/advisories/GHSA-wpx3-h5g8-qr3wExploit, Vendor Advisory
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/saitoha/libsixel/security/advisories/GHSA-wpx3-h5g8-qr3wExploit, Vendor Advisory
Impacted products
Vendor Product Version
saitoha libsixel *
To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:saitoha:libsixel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "07609BEC-B5AE-4004-8DF0-DCA17A16DF56",
              "versionEndExcluding": "1.8.7-r2",
              "versionStartIncluding": "1.0.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
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  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "libsixel is a SIXEL encoder/decoder implementation derived from kmiya\u0027s sixel. From  to 1.8.7-r1, a wrong NULL check after an allocation call in sixel_decode_raw and sixel_decode causes a NULL pointer dereference whenever the allocation fails. The check tests the address of the output parameter (always non-NULL) instead of the value the malloc returned. On allocation failure, the function continues and writes through a NULL pointer, crashing the process. This is a denial of service against any caller of these public APIs that hits a low-memory condition. This vulnerability is fixed in 1.8.7-r2."
    }
  ],
  "id": "CVE-2026-44638",
  "lastModified": "2026-05-15T17:54:09.270",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "LOCAL",
          "availabilityImpact": "LOW",
          "baseScore": 2.5,
          "baseSeverity": "LOW",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L",
          "version": "3.1"
        },
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        "source": "security-advisories@github.com",
        "type": "Secondary"
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          "attackVector": "LOCAL",
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          "baseScore": 2.5,
          "baseSeverity": "LOW",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L",
          "version": "3.1"
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        "exploitabilityScore": 1.0,
        "impactScore": 1.4,
        "source": "nvd@nist.gov",
        "type": "Primary"
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  "published": "2026-05-14T20:17:08.983",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ],
      "url": "https://github.com/saitoha/libsixel/security/advisories/GHSA-wpx3-h5g8-qr3w"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "tags": [
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        "Vendor Advisory"
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      "url": "https://github.com/saitoha/libsixel/security/advisories/GHSA-wpx3-h5g8-qr3w"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        },
        {
          "lang": "en",
          "value": "CWE-690"
        }
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      "source": "security-advisories@github.com",
      "type": "Secondary"
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          "value": "CWE-476"
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      ],
      "source": "nvd@nist.gov",
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    }
  ]
}


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