Vulnerability-Lookup

GHSA-93Q6-WWJH-JC6H

Vulnerability from github – Published: 2026-07-02 19:08 – Updated: 2026-07-02 19:08

Summary

@asymmetric-effort/specifyjs: CSS expression sanitization is bypassable in renderToString

Details

Finding

Location: core/src/server/render-to-string.ts:307-311

CSS value sanitization stripped expression( and url(javascript: using simple regex, but could be bypassed with CSS unicode escapes (\65xpression(), null bytes, or CSS comments (exp/**/ression().

Mitigating Factor: These CSS injection vectors only work in legacy browsers (IE6-IE10). SpecifyJS targets modern browsers.

Status

Fixed in v0.2.136 — CSS sanitization now normalizes unicode escapes and strips CSS comments before pattern matching. Also checks for behavior:, -moz-binding, and -o-link patterns.

Severity

5.3 (Medium)


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

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@asymmetric-effort/specifyjs"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.2.136"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-50290"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-02T19:08:45Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "## Finding\n\n**Location**: `core/src/server/render-to-string.ts:307-311`\n\nCSS value sanitization stripped `expression(` and `url(javascript:` using simple regex, but could be bypassed with CSS unicode escapes (`\\65xpression(`), null bytes, or CSS comments (`exp/**/ression(`).\n\n**Mitigating Factor**: These CSS injection vectors only work in legacy browsers (IE6-IE10). SpecifyJS targets modern browsers.\n\n## Status\n\n**Fixed in v0.2.136** \u2014 CSS sanitization now normalizes unicode escapes and strips CSS comments before pattern matching. Also checks for `behavior:`, `-moz-binding`, and `-o-link` patterns.",
  "id": "GHSA-93q6-wwjh-jc6h",
  "modified": "2026-07-02T19:08:45Z",
  "published": "2026-07-02T19:08:45Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/asymmetric-effort/specifyjs/security/advisories/GHSA-93q6-wwjh-jc6h"
    },
    {
      "type": "WEB",
      "url": "https://github.com/asymmetric-effort/specifyjs/commit/25d1fb491d99479efdf501f5f75e0bb80c908f0a"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/asymmetric-effort/specifyjs"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "@asymmetric-effort/specifyjs: CSS expression sanitization is bypassable in renderToString"
}

CVE-2026-50290 (GCVE-0-2026-50290)

Vulnerability from cvelistv5 – Published: 2026-08-21 19:55 – Updated: 2026-08-21 20:07

Title

@asymmetric-effort/specifyjs: CSS expression sanitization is bypassable in renderToString

Summary

SpecifyJS is a declarative TypeScript user interface framework. Prior to version 0.2.136, CSS value sanitization stripped `expression(` and `url(javascript:` using simple regex, but could be bypassed with CSS unicode escapes (`\65xpression(`), null bytes, or CSS comments (`exp/**/ression(`). These CSS injection vectors only work in legacy browsers (IE6-IE10). SpecifyJS targets modern browsers. Starting in version 0.2.136, CSS sanitization now normalizes unicode escapes and strips CSS comments before pattern matching. Also checks for `behavior:`, `-moz-binding`, and `-o-link` patterns.

Severity

5.3 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-21 20:07 UTC

CWE

CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Assigner

GitHub_M mitre root

References

2 references

URL	Tags
https://github.com/asymmetric-effort/specifyjs/se…	x_refsource_CONFIRM
https://github.com/asymmetric-effort/specifyjs/co…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
asymmetric-effort	specifyjs	Affected: < 0.2.136

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JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-50290",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-21T20:07:03.359376Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-21T20:07:10.712Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "specifyjs",
          "vendor": "asymmetric-effort",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.2.136"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "SpecifyJS is a declarative TypeScript user interface framework. Prior to version 0.2.136, CSS value sanitization stripped `expression(` and `url(javascript:` using simple regex, but could be bypassed with CSS unicode escapes (`\\65xpression(`), null bytes, or CSS comments (`exp/**/ression(`). These CSS injection vectors only work in legacy browsers (IE6-IE10). SpecifyJS targets modern browsers. Starting in version 0.2.136, CSS sanitization now normalizes unicode escapes and strips CSS comments before pattern matching. Also checks for `behavior:`, `-moz-binding`, and `-o-link` patterns."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "LOW",
            "subIntegrityImpact": "LOW",
            "userInteraction": "PASSIVE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "CWE-79: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-21T19:55:51.086Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/asymmetric-effort/specifyjs/security/advisories/GHSA-93q6-wwjh-jc6h",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/asymmetric-effort/specifyjs/security/advisories/GHSA-93q6-wwjh-jc6h"
        },
        {
          "name": "https://github.com/asymmetric-effort/specifyjs/commit/25d1fb491d99479efdf501f5f75e0bb80c908f0a",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/asymmetric-effort/specifyjs/commit/25d1fb491d99479efdf501f5f75e0bb80c908f0a"
        }
      ],
      "source": {
        "advisory": "GHSA-93q6-wwjh-jc6h",
        "discovery": "UNKNOWN"
      },
      "title": "@asymmetric-effort/specifyjs: CSS expression sanitization is bypassable in renderToString"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-50290",
    "datePublished": "2026-08-21T19:55:51.086Z",
    "dateReserved": "2026-06-04T16:26:05.986Z",
    "dateUpdated": "2026-08-21T20:07:10.712Z",
    "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.