Vulnerability-Lookup

CVE-2026-116582 (GCVE-0-2026-116582)

Vulnerability from cvelistv5 – Published: 2026-10-26 20:46 – Updated: 2026-10-26 20:46

Title

Seroval: Script injection through RegExp sources in serialized output

Summary

Seroval facilitates JavaScript value stringification, including complex structures beyond JSON.stringify capabilities. Prior to 1.0.0 and from 1.5.5 until 1.6.10, the JavaScript-output APIs serialize a RegExp source containing a less-than character without the escaping needed for an HTML script element. An application is affected when it builds regular expression syntax from untrusted input, serializes that RegExp through serialize, serializeAsync, crossSerialize, crossSerializeAsync, crossSerializeStream, Serializer, or compileJSON, and embeds the result in an HTML script element. The crafted source can terminate the element and execute script in the page received by another user. This issue is fixed in version 1.6.10.

Severity

4.7 (Medium)


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

CWE

CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-116 - Improper Encoding or Escaping of Output

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7994 records in the last 180 days details

References

3 references

URL	Tags
https://github.com/lxsmnsyc/seroval/security/advi…	x_refsource_CONFIRM
https://github.com/lxsmnsyc/seroval/commit/f94ee0…	x_refsource_MISC
https://github.com/lxsmnsyc/seroval/releases/tag/…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version	CPE status
lxsmnsyc	seroval	Affected: < 1.0.0 Affected: >= 1.5.5, < 1.6.10	guessed

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "seroval",
          "vendor": "lxsmnsyc",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.0.0"
            },
            {
              "status": "affected",
              "version": "\u003e= 1.5.5, \u003c 1.6.10"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Seroval facilitates JavaScript value stringification, including complex structures beyond JSON.stringify capabilities. Prior to 1.0.0 and from 1.5.5 until 1.6.10, the JavaScript-output APIs serialize a RegExp source containing a less-than character without the escaping needed for an HTML script element. An application is affected when it builds regular expression syntax from untrusted input, serializes that RegExp through serialize, serializeAsync, crossSerialize, crossSerializeAsync, crossSerializeStream, Serializer, or compileJSON, and embeds the result in an HTML script element. The crafted source can terminate the element and execute script in the page received by another user. This issue is fixed in version 1.6.10."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 4.7,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
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            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "CWE-79: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-116",
              "description": "CWE-116: Improper Encoding or Escaping of Output",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-26T20:46:46.069Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/lxsmnsyc/seroval/security/advisories/GHSA-9wx9-5pv9-3349",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/lxsmnsyc/seroval/security/advisories/GHSA-9wx9-5pv9-3349"
        },
        {
          "name": "https://github.com/lxsmnsyc/seroval/commit/f94ee0b63936dae954ff50d5b5e8ea7cb9b284e6",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/lxsmnsyc/seroval/commit/f94ee0b63936dae954ff50d5b5e8ea7cb9b284e6"
        },
        {
          "name": "https://github.com/lxsmnsyc/seroval/releases/tag/seroval@1.6.10",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/lxsmnsyc/seroval/releases/tag/seroval@1.6.10"
        }
      ],
      "source": {
        "advisory": "GHSA-9wx9-5pv9-3349",
        "discovery": "UNKNOWN"
      },
      "title": "Seroval: Script injection through RegExp sources in serialized output"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-116582",
    "datePublished": "2026-10-26T20:46:46.069Z",
    "dateReserved": "2026-10-26T15:03:39.035Z",
    "dateUpdated": "2026-10-26T20:46:46.069Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
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      "date": "2026-10-29",
      "epss": "0.00188",
      "percentile": "0.08386"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "seroval",
                "vendor": "lxsmnsyc",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003c 1.0.0"
                  },
                  {
                    "status": "affected",
                    "version": "\u003e= 1.5.5, \u003c 1.6.10"
                  }
                ]
              }
            ],
            "source": "security-advisories@github.com"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "Seroval facilitates JavaScript value stringification, including complex structures beyond JSON.stringify capabilities. Prior to 1.0.0 and from 1.5.5 until 1.6.10, the JavaScript-output APIs serialize a RegExp source containing a less-than character without the escaping needed for an HTML script element. An application is affected when it builds regular expression syntax from untrusted input, serializes that RegExp through serialize, serializeAsync, crossSerialize, crossSerializeAsync, crossSerializeStream, Serializer, or compileJSON, and embeds the result in an HTML script element. The crafted source can terminate the element and execute script in the page received by another user. This issue is fixed in version 1.6.10."
          }
        ],
        "id": "CVE-2026-116582",
        "lastModified": "2026-10-26T21:18:16.613",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "HIGH",
                "attackVector": "NETWORK",
                "availabilityImpact": "NONE",
                "baseScore": 4.7,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "LOW",
                "integrityImpact": "LOW",
                "privilegesRequired": "NONE",
                "scope": "CHANGED",
                "userInteraction": "REQUIRED",
                "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N",
                "version": "3.1"
              },
              "exploitabilityScore": 1.6,
              "impactScore": 2.7,
              "source": "security-advisories@github.com",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-10-26T21:18:16.267",
        "references": [
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/lxsmnsyc/seroval/commit/f94ee0b63936dae954ff50d5b5e8ea7cb9b284e6"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/lxsmnsyc/seroval/releases/tag/seroval@1.6.10"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/lxsmnsyc/seroval/security/advisories/GHSA-9wx9-5pv9-3349"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Deferred",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-79"
              },
              {
                "lang": "en",
                "value": "CWE-116"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Primary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-10-27T05:17:52+00:00",
      "cve": "CVE-2026-116582",
      "id": "CVE-2026-116582",
      "initial_release_date": "2026-10-26T20:46:46.069000+00:00",
      "product_status:known_affected": "1",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "seroval: seroval: Cross-site scripting via improper regular expression serialization",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-116582.json",
      "version": "3"
    }
  }
}

FKIE_CVE-2026-116582

Vulnerability from fkie_nvd - Published: 2026-10-26 21:18 - Updated: 2026-10-26 21:18

Severity

4.7 (Medium) - CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/lxsmnsyc/seroval/commit/f94ee0b63936dae954ff50d5b5e8ea7cb9b284e6
	security-advisories@github.com	https://github.com/lxsmnsyc/seroval/releases/tag/seroval@1.6.10
	security-advisories@github.com	https://github.com/lxsmnsyc/seroval/security/advisories/GHSA-9wx9-5pv9-3349

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "seroval",
          "vendor": "lxsmnsyc",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.0.0"
            },
            {
              "status": "affected",
              "version": "\u003e= 1.5.5, \u003c 1.6.10"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Seroval facilitates JavaScript value stringification, including complex structures beyond JSON.stringify capabilities. Prior to 1.0.0 and from 1.5.5 until 1.6.10, the JavaScript-output APIs serialize a RegExp source containing a less-than character without the escaping needed for an HTML script element. An application is affected when it builds regular expression syntax from untrusted input, serializes that RegExp through serialize, serializeAsync, crossSerialize, crossSerializeAsync, crossSerializeStream, Serializer, or compileJSON, and embeds the result in an HTML script element. The crafted source can terminate the element and execute script in the page received by another user. This issue is fixed in version 1.6.10."
    }
  ],
  "id": "CVE-2026-116582",
  "lastModified": "2026-10-26T21:18:16.613",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 4.7,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 2.7,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-10-26T21:18:16.267",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/lxsmnsyc/seroval/commit/f94ee0b63936dae954ff50d5b5e8ea7cb9b284e6"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/lxsmnsyc/seroval/releases/tag/seroval@1.6.10"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/lxsmnsyc/seroval/security/advisories/GHSA-9wx9-5pv9-3349"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-79"
        },
        {
          "lang": "en",
          "value": "CWE-116"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}

GHSA-9WX9-5PV9-3349

Vulnerability from github – Published: 2026-10-28 21:17 – Updated: 2026-10-28 21:17

Summary

Seroval: Script injection through RegExp sources in serialized output

Details

Summary

seroval writes a RegExp as a regular expression literal. In affected versions, the < character in a RegExp source is written without escaping. A source built from untrusted input can then end the HTML <script> element that the serialized output is placed in, and run script in the page.

Details

seroval escapes < in strings, so string values cannot end a <script> element. RegExp sources did not get the same escaping:

Versions before 1.0.0 wrote the source as is.
Version 1.5.5 stopped escaping < in RegExp sources, so that named groups and lookbehinds keep working. This removed the escaping for every < in a source.

These functions are affected:

serialize, serializeAsync
crossSerialize, crossSerializeAsync, crossSerializeStream
the Serializer class
compileJSON

toJSON, fromJSON, toCrossJSON and fromCrossJSON are not affected, because they never produce JavaScript.

Impact

An application is affected when all of these are true:

It builds a RegExp from untrusted input that is used as regular expression syntax. Input passed through an escaping helper (such as an escapeRegExp function) is not enough to exploit this.
It serializes that RegExp with one of the functions above.
It places the output inside an HTML <script> element, as server rendering usually does.

In that case an attacker can run script in the page of any user who receives that output.

Patches

Fixed in 1.6.10. A RegExp whose source contains < is now written with the RegExp constructor and an escaped string source. Named groups and lookbehinds keep working.

Workarounds

If you cannot upgrade:

Do not serialize a RegExp built from untrusted pattern syntax. Send its source and flags as strings, and build the RegExp on the client.
Or reject patterns that contain < before they reach the serializer.

Severity

4.7 (Medium)


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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "seroval"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.5.5"
            },
            {
              "fixed": "1.6.10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "seroval"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.0.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-116582"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-116",
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-28T21:17:31Z",
    "nvd_published_at": "2026-10-26T21:18:16Z",
    "severity": "MODERATE"
  },
  "details": "### Summary\n\nseroval writes a `RegExp` as a regular expression literal. In affected versions, the `\u003c` character in a `RegExp` source is written without escaping. A source built from untrusted input can then end the HTML `\u003cscript\u003e` element that the serialized output is placed in, and run script in the page.\n\n### Details\n\nseroval escapes `\u003c` in strings, so string values cannot end a `\u003cscript\u003e` element. `RegExp` sources did not get the same escaping:\n\n- Versions before 1.0.0 wrote the source as is.\n- Version 1.5.5 stopped escaping `\u003c` in `RegExp` sources, so that named groups and lookbehinds keep working. This removed the escaping for every `\u003c` in a source.\n\nThese functions are affected:\n\n- `serialize`, `serializeAsync`\n- `crossSerialize`, `crossSerializeAsync`, `crossSerializeStream`\n- the `Serializer` class\n- `compileJSON`\n\n`toJSON`, `fromJSON`, `toCrossJSON` and `fromCrossJSON` are not affected, because they never produce JavaScript.\n\n### Impact\n\nAn application is affected when all of these are true:\n\n1. It builds a `RegExp` from untrusted input that is used as regular expression syntax. Input passed through an escaping helper (such as an `escapeRegExp` function) is not enough to exploit this.\n2. It serializes that `RegExp` with one of the functions above.\n3. It places the output inside an HTML `\u003cscript\u003e` element, as server rendering usually does.\n\nIn that case an attacker can run script in the page of any user who receives that output.\n\n### Patches\n\nFixed in 1.6.10. A `RegExp` whose source contains `\u003c` is now written with the `RegExp` constructor and an escaped string source. Named groups and lookbehinds keep working.\n\n### Workarounds\n\nIf you cannot upgrade:\n\n- Do not serialize a `RegExp` built from untrusted pattern syntax. Send its source and flags as strings, and build the `RegExp` on the client.\n- Or reject patterns that contain `\u003c` before they reach the serializer.",
  "id": "GHSA-9wx9-5pv9-3349",
  "modified": "2026-10-28T21:17:31Z",
  "published": "2026-10-28T21:17:31Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/lxsmnsyc/seroval/security/advisories/GHSA-9wx9-5pv9-3349"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-116582"
    },
    {
      "type": "WEB",
      "url": "https://github.com/lxsmnsyc/seroval/commit/f94ee0b63936dae954ff50d5b5e8ea7cb9b284e6"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/lxsmnsyc/seroval"
    },
    {
      "type": "WEB",
      "url": "https://github.com/lxsmnsyc/seroval/releases/tag/seroval@1.6.10"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Seroval: Script injection through RegExp sources in serialized output"
}

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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

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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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CVE-2026-116582 (GCVE-0-2026-116582)

FKIE_CVE-2026-116582

GHSA-9WX9-5PV9-3349

Summary

Details

Impact

Patches

Workarounds

Tags

Sightings

Nomenclature

Vulnerability timeline

Related by attack behaviour