Vulnerability-Lookup

CVE-2026-48591 (GCVE-0-2026-48591)

Vulnerability from cvelistv5 – Published: 2026-06-17 16:42 – Updated: 2026-06-18 04:45

Title

Stored XSS via unescaped HTML attribute values in earmark

Summary

Improper Neutralization of Script in Attributes in a Web Page vulnerability in pragdave earmark allows stored cross-site scripting via unescaped HTML attribute values. 'Elixir.Earmark.Transform':_make_att1/2 in lib/earmark/transform.ex splices attribute values verbatim between two literal " bytes: [" ", name, "=\"", value, "\""]. Text nodes are routed through the existing escape function which encodes " as ", but attribute values never visit that path. A markdown link whose URL or title contains a bare " closes the attribute early and lets the trailing bytes be parsed by the browser as fresh HTML attributes. For example, [click](http://example.com/?a=x" onerror="alert(1)) renders as <a href="http://example.com/?a=x" onerror="alert(1)">click</a>, executing arbitrary JavaScript in the victim's browser. The earmark library is no longer maintained and has been retired on Hex. No patched version will be released. All releases from 1.4.1 onward are affected, and users should migrate to a maintained Markdown library such as MDEx. This issue affects earmark from 1.4.1 onward.

Severity

4.8 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-83 - Improper Neutralization of Script in Attributes in a Web Page

Assigner

EEF

References

2 references

URL	Tags
https://cna.erlef.org/cves/CVE-2026-48591.html	relatedthird-party-advisory
https://osv.dev/vulnerability/EEF-CVE-2026-48591	related

Impacted products

2 products

Vendor	Product	Version
pragdave	earmark	Affected: 1.4.1 , < * (semver) cpe:2.3:a:pragdave:earmark::::::::
pragdave	earmark	Affected: 8236a0570bd894b50e360da08131ec3294c20799 , < * (git) cpe:2.3:a:pragdave:earmark::::::::

Credits

Peter Ullrich Robert Dober Jonatan Männchen / EEF

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-48591

Vulnerability from fkie_nvd - Published: 2026-06-17 18:18 - Updated: 2026-06-17 19:18

Severity

4.8 (Medium) - CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

Summary

References

	URL	Tags
	6b3ad84c-e1a6-4bf7-a703-f496b71e49db	https://cna.erlef.org/cves/CVE-2026-48591.html
	6b3ad84c-e1a6-4bf7-a703-f496b71e49db	https://osv.dev/vulnerability/EEF-CVE-2026-48591

Impacted products

	Vendor	Product	Version

JSON

To clipboard

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    {
      "lang": "en",
      "value": "Improper Neutralization of Script in Attributes in a Web Page vulnerability in pragdave earmark allows stored cross-site scripting via unescaped HTML attribute values.\n\n\u0027Elixir.Earmark.Transform\u0027:_make_att1/2 in lib/earmark/transform.ex splices attribute values verbatim between two literal \" bytes: [\" \", name, \"=\\\"\", value, \"\\\"\"]. Text nodes are routed through the existing escape function which encodes \" as \u0026quot;, but attribute values never visit that path. A markdown link whose URL or title contains a bare \" closes the attribute early and lets the trailing bytes be parsed by the browser as fresh HTML attributes. For example, [click](http://example.com/?a=x\" onerror=\"alert(1)) renders as \u003ca href=\"http://example.com/?a=x\" onerror=\"alert(1)\"\u003eclick\u003c/a\u003e, executing arbitrary JavaScript in the victim\u0027s browser.\n\nThe earmark library is no longer maintained and has been retired on Hex. No patched version will be released. All releases from 1.4.1 onward are affected, and users should migrate to a maintained Markdown library such as MDEx.\n\nThis issue affects earmark from 1.4.1 onward."
    }
  ],
  "id": "CVE-2026-48591",
  "lastModified": "2026-06-17T19:18:09.000",
  "metrics": {
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "LOCAL",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 4.8,
          "baseSeverity": "MEDIUM",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "LOW",
          "subIntegrityImpact": "LOW",
          "userInteraction": "PASSIVE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/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",
          "version": "4.0",
          "vulnAvailabilityImpact": "NONE",
          "vulnConfidentialityImpact": "LOW",
          "vulnIntegrityImpact": "LOW",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-48591",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-06-17T18:25:40.841347Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-06-17T18:18:04.370",
  "references": [
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://cna.erlef.org/cves/CVE-2026-48591.html"
    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-48591"
    }
  ],
  "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-83"
        }
      ],
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "type": "Secondary"
    }
  ]
}

GHSA-52MM-H59V-F3C7

Vulnerability from github – Published: 2026-06-17 18:35 – Updated: 2026-06-18 14:47

Summary

earmark: Stored XSS via unescaped HTML attribute values

Details

Improper Neutralization of Script in Attributes in a Web Page vulnerability in pragdave earmark allows stored cross-site scripting via unescaped HTML attribute values.

'Elixir.Earmark.Transform':_make_att1/2 in lib/earmark/transform.ex splices attribute values verbatim between two literal " bytes: [" ", name, "=\"", value, "\""]. Text nodes are routed through the existing escape function which encodes " as ", but attribute values never visit that path. A markdown link whose URL or title contains a bare " closes the attribute early and lets the trailing bytes be parsed by the browser as fresh HTML attributes. For example, click.

The earmark library is no longer maintained and has been retired on Hex. No patched version will be released. All releases from 1.4.1 onward are affected, and users should migrate to a maintained Markdown library such as MDEx.

This issue affects earmark from 1.4.1 onward.

Severity

4.8 (Medium)


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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Hex",
        "name": "earmark"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.4.1"
            },
            {
              "last_affected": "1.5.0-pre1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-48591"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79",
      "CWE-83"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-18T14:47:16Z",
    "nvd_published_at": "2026-06-17T18:18:04Z",
    "severity": "MODERATE"
  },
  "details": "Improper Neutralization of Script in Attributes in a Web Page vulnerability in pragdave earmark allows stored cross-site scripting via unescaped HTML attribute values.\n\n\u0027Elixir.Earmark.Transform\u0027:_make_att1/2 in lib/earmark/transform.ex splices attribute values verbatim between two literal \" bytes: [\" \", name, \"=\\\"\", value, \"\\\"\"]. Text nodes are routed through the existing escape function which encodes \" as \u0026quot;, but attribute values never visit that path. A markdown link whose URL or title contains a bare \" closes the attribute early and lets the trailing bytes be parsed by the browser as fresh HTML attributes. For example, [click](http://example.com/?a=x\" onerror=\"alert(1)) renders as \u003ca href=\"http://example.com/?a=x\" onerror=\"alert(1)\"\u003eclick\u003c/a\u003e, executing arbitrary JavaScript in the victim\u0027s browser.\n\nThe earmark library is no longer maintained and has been retired on Hex. No patched version will be released. All releases from 1.4.1 onward are affected, and users should migrate to a maintained Markdown library such as MDEx.\n\nThis issue affects earmark from 1.4.1 onward.",
  "id": "GHSA-52mm-h59v-f3c7",
  "modified": "2026-06-18T14:47:16Z",
  "published": "2026-06-17T18:35:58Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-48591"
    },
    {
      "type": "WEB",
      "url": "https://cna.erlef.org/cves/CVE-2026-48591.html"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/pragdave/earmark"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-48591"
    }
  ],
  "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:N/SC:L/SI:L/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "earmark: Stored XSS via unescaped HTML attribute values"
}

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.

Action not permitted

CVE-2026-48591 (GCVE-0-2026-48591)

FKIE_CVE-2026-48591

GHSA-52MM-H59V-F3C7

Tags

Sightings

Nomenclature