Vulnerability-Lookup

GHSA-6JXJ-PX6V-747W

Vulnerability from github – Published: 2026-10-29 16:35 – Updated: 2026-10-29 16:35

Summary

Crass: Deeply nested CSS blocks and functions can trigger a SystemStackError or excessive memory usage

Details

Impact

Crass recursively parses CSS simple blocks and functions without a depth guard. An attacker-controlled value containing many deeply nested blocks can recurse until Ruby raises SystemStackError: stack level too deep, or can cause excessive memory usage.

Patches

This is fixed in Crass 1.0.7, which adds a configurable depth limit with a conservative default.

Workarounds

Add SystemStackError handling around Crass calls in your application. Buy more RAM.

Severity

6.3 (Medium)


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

Show details on source website

JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "crass"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.0.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-61846"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-29T16:35:16Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Impact\n\nCrass recursively parses CSS simple blocks and functions without a depth guard. An attacker-controlled value containing many deeply nested blocks can recurse until Ruby raises `SystemStackError: stack level too deep`, or can cause excessive memory usage.\n\n### Patches\n\nThis is fixed in Crass 1.0.7, which adds a configurable depth limit with a conservative default.\n\n### Workarounds\n\nAdd `SystemStackError` handling around Crass calls in your application. Buy more RAM.",
  "id": "GHSA-6jxj-px6v-747w",
  "modified": "2026-10-29T16:35:16Z",
  "published": "2026-10-29T16:35:16Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/rgrove/crass/security/advisories/GHSA-6jxj-px6v-747w"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rgrove/crass/commit/cf68287356ec6e20d51cfc4a2d0c3912b7334e99"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/rgrove/crass"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rgrove/crass/releases/tag/v1.0.7"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Crass: Deeply nested CSS blocks and functions can trigger a SystemStackError or excessive memory usage"
}

CVE-2026-61846 (GCVE-0-2026-61846)

Vulnerability from cvelistv5 – Published: 2026-10-30 18:43 – Updated: 2026-10-30 18:43

Title

Crass: Deeply nested CSS blocks and functions can trigger a SystemStackError or excessive memory usage

Summary

Crass is a Ruby CSS parser that's fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, Crass recursively parses `CSS simple blocks and functions` without a depth guard. An attacker-controlled CSS value containing deeply nested blocks or functions can recurse until Ruby raises `SystemStackError`: stack level too deep, or cause excessive memory usage. Version 1.0.7 adds a configurable depth limit with a conservative default. This issue is fixed in version 1.0.7.

Severity

6.3 (Medium)


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

CWE

CWE-674 - Uncontrolled Recursion

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7963 records in the last 180 days details

References

3 references

URL	Tags
https://github.com/rgrove/crass/security/advisori…	x_refsource_CONFIRM
https://github.com/rgrove/crass/commit/cf68287356…	x_refsource_MISC
https://github.com/rgrove/crass/releases/tag/v1.0.7	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
rgrove	crass	Affected: < 1.0.7

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "crass",
          "vendor": "rgrove",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.0.7"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Crass is a Ruby CSS parser that\u0027s fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, Crass recursively parses `CSS simple blocks and functions` without a depth guard. An attacker-controlled CSS value containing deeply nested blocks or functions can recurse until Ruby raises `SystemStackError`: stack level too deep, or cause excessive memory usage. Version 1.0.7 adds a configurable depth limit with a conservative default. This issue is fixed in version 1.0.7."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 6.3,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "LOW",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L",
            "version": "4.0",
            "vulnAvailabilityImpact": "LOW",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-674",
              "description": "CWE-674: Uncontrolled Recursion",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-30T18:43:25.373Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/rgrove/crass/security/advisories/GHSA-6jxj-px6v-747w",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/rgrove/crass/security/advisories/GHSA-6jxj-px6v-747w"
        },
        {
          "name": "https://github.com/rgrove/crass/commit/cf68287356ec6e20d51cfc4a2d0c3912b7334e99",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/rgrove/crass/commit/cf68287356ec6e20d51cfc4a2d0c3912b7334e99"
        },
        {
          "name": "https://github.com/rgrove/crass/releases/tag/v1.0.7",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/rgrove/crass/releases/tag/v1.0.7"
        }
      ],
      "source": {
        "advisory": "GHSA-6jxj-px6v-747w",
        "discovery": "UNKNOWN"
      },
      "title": "Crass: Deeply nested CSS blocks and functions can trigger a SystemStackError or excessive memory usage"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-61846",
    "datePublished": "2026-10-30T18:43:25.373Z",
    "dateReserved": "2026-07-10T20:28:17.513Z",
    "dateUpdated": "2026-10-30T18:43:25.373Z",
    "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.

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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.

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