Vulnerability-Lookup

CVE-2026-126359 (GCVE-0-2026-126359)

Vulnerability from cvelistv5 – Published: 2026-11-12 22:22 – Updated: 2026-11-12 22:22

Title

Hono: `css` helper does not escape a closing tag split between the template and an interpolated value, allowing HTML injection

Summary

Hono is a Web application framework that provides support for any JavaScript runtime. From 3.12.0 until 4.13.16, the css helper in hono/css escapes interpolated string values separately and therefore fails to neutralize a closing style tag when < ends the template text or a preceding value and / begins the next attacker-controlled value. During server-side rendering, the combined output can close the <Style /> element early and cause the remainder of the interpolated value to be interpreted as HTML. Applications that place an untrusted string immediately after < in a css template, including adjacent untrusted interpolations, can expose viewers to attacker-controlled HTML or script and information accessible to that page. Other uses of the css helper are not affected. This issue is fixed in version 4.13.16.

Severity

3.4 (Low)


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

CWE

CWE-79 - Improper Neutralization of Input During Web Page Generation

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7820 records in the last 180 days details

References

3 references

URL	Tags
https://github.com/honojs/hono/security/advisorie…	x_refsource_CONFIRM
https://github.com/honojs/hono/commit/15bbd96ad1b…	x_refsource_MISC
https://github.com/honojs/hono/releases/tag/v4.13.16	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version	CPE status
honojs	hono	Affected: >= 3.12.0, < 4.13.16	guessed

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "hono",
          "vendor": "honojs",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 3.12.0, \u003c 4.13.16"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Hono is a Web application framework that provides support for any JavaScript runtime. From 3.12.0 until 4.13.16, the css helper in hono/css escapes interpolated string values separately and therefore fails to neutralize a closing style tag when \u0026lt; ends the template text or a preceding value and / begins the next attacker-controlled value. During server-side rendering, the combined output can close the \u0026lt;Style /\u0026gt; element early and cause the remainder of the interpolated value to be interpreted as HTML. Applications that place an untrusted string immediately after \u0026lt; in a css template, including adjacent untrusted interpolations, can expose viewers to attacker-controlled HTML or script and information accessible to that page. Other uses of the css helper are not affected. This issue is fixed in version 4.13.16."
        }
      ],
      "metrics": [
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            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
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            "baseScore": 3.4,
            "baseSeverity": "LOW",
            "confidentialityImpact": "LOW",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:N/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "CWE-79: Improper Neutralization of Input During Web Page Generation",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-12T22:22:32.161Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/honojs/hono/security/advisories/GHSA-3gg2-335m-rxc6",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/honojs/hono/security/advisories/GHSA-3gg2-335m-rxc6"
        },
        {
          "name": "https://github.com/honojs/hono/commit/15bbd96ad1b62a0b189db4fd8dc7bf8ef280c513",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/honojs/hono/commit/15bbd96ad1b62a0b189db4fd8dc7bf8ef280c513"
        },
        {
          "name": "https://github.com/honojs/hono/releases/tag/v4.13.16",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/honojs/hono/releases/tag/v4.13.16"
        }
      ],
      "source": {
        "advisory": "GHSA-3gg2-335m-rxc6",
        "discovery": "UNKNOWN"
      },
      "title": "Hono: `css` helper does not escape a closing tag split between the template and an interpolated value, allowing HTML injection"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-126359",
    "datePublished": "2026-11-12T22:22:32.161Z",
    "dateReserved": "2026-11-10T21:12:01.228Z",
    "dateUpdated": "2026-11-12T22:22:32.161Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "hono",
                "vendor": "honojs",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003e= 3.12.0, \u003c 4.13.16"
                  }
                ]
              }
            ],
            "source": "security-advisories@github.com"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "Hono is a Web application framework that provides support for any JavaScript runtime. From 3.12.0 until 4.13.16, the css helper in hono/css escapes interpolated string values separately and therefore fails to neutralize a closing style tag when \u0026lt; ends the template text or a preceding value and / begins the next attacker-controlled value. During server-side rendering, the combined output can close the \u0026lt;Style /\u0026gt; element early and cause the remainder of the interpolated value to be interpreted as HTML. Applications that place an untrusted string immediately after \u0026lt; in a css template, including adjacent untrusted interpolations, can expose viewers to attacker-controlled HTML or script and information accessible to that page. Other uses of the css helper are not affected. This issue is fixed in version 4.13.16."
          }
        ],
        "id": "CVE-2026-126359",
        "lastModified": "2026-11-13T00:20:11.370",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "HIGH",
                "attackVector": "NETWORK",
                "availabilityImpact": "NONE",
                "baseScore": 3.4,
                "baseSeverity": "LOW",
                "confidentialityImpact": "LOW",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "CHANGED",
                "userInteraction": "REQUIRED",
                "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:N/A:N",
                "version": "3.1"
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              "source": "security-advisories@github.com",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-11-13T00:20:11.233",
        "references": [
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/honojs/hono/commit/15bbd96ad1b62a0b189db4fd8dc7bf8ef280c513"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/honojs/hono/releases/tag/v4.13.16"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/honojs/hono/security/advisories/GHSA-3gg2-335m-rxc6"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Deferred",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-79"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Primary"
          }
        ]
      }
    }
  }
}

FKIE_CVE-2026-126359

Vulnerability from fkie_nvd - Published: 2026-11-13 00:20 - Updated: 2026-11-13 00:20

Severity

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

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/honojs/hono/commit/15bbd96ad1b62a0b189db4fd8dc7bf8ef280c513
	security-advisories@github.com	https://github.com/honojs/hono/releases/tag/v4.13.16
	security-advisories@github.com	https://github.com/honojs/hono/security/advisories/GHSA-3gg2-335m-rxc6

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "hono",
          "vendor": "honojs",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 3.12.0, \u003c 4.13.16"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Hono is a Web application framework that provides support for any JavaScript runtime. From 3.12.0 until 4.13.16, the css helper in hono/css escapes interpolated string values separately and therefore fails to neutralize a closing style tag when \u0026lt; ends the template text or a preceding value and / begins the next attacker-controlled value. During server-side rendering, the combined output can close the \u0026lt;Style /\u0026gt; element early and cause the remainder of the interpolated value to be interpreted as HTML. Applications that place an untrusted string immediately after \u0026lt; in a css template, including adjacent untrusted interpolations, can expose viewers to attacker-controlled HTML or script and information accessible to that page. Other uses of the css helper are not affected. This issue is fixed in version 4.13.16."
    }
  ],
  "id": "CVE-2026-126359",
  "lastModified": "2026-11-13T00:20:11.370",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 3.4,
          "baseSeverity": "LOW",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 1.4,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-11-13T00:20:11.233",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/honojs/hono/commit/15bbd96ad1b62a0b189db4fd8dc7bf8ef280c513"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/honojs/hono/releases/tag/v4.13.16"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/honojs/hono/security/advisories/GHSA-3gg2-335m-rxc6"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-79"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}

GHSA-3GG2-335M-RXC6

Vulnerability from github – Published: 2026-11-12 23:22 – Updated: 2026-11-12 23:22

Summary

Hono: `css` helper does not escape a closing tag split between the template and an interpolated value, allowing HTML injection

Details

Summary

The css helper in hono/css escapes a / that follows < inside an interpolated value so that a value cannot close the <style> element. The check only looks inside each value. When the text before a value ends with <, whether that is the template itself or an earlier interpolated value, and the next value starts with /, the / is not escaped and the combined output contains an unescaped closing tag.

Details

Interpolated string values are escaped one at a time before they are joined with the surrounding template text. The rule that neutralizes </ therefore cannot see a < that belongs to the template. A template such as a content declaration that opens with a literal < and interpolates a string right after it produces a raw </style> when that string starts with /style>. During server-side rendering the <Style /> element is closed early and the rest of the value is interpreted as HTML.

This issue arises only when < is the last character before an interpolation in a css template, either written in the template or supplied by a preceding value, and the interpolated value is controlled by a client.

Impact

A client that controls such a value can inject HTML, including script, into the page rendered on the server.

This may lead to:

Execution of attacker-controlled script in the browser of a user who views the page
Exposure of information available to that page

This issue affects applications that interpolate untrusted strings into a css template immediately after a <, including two adjacent interpolations such as ${prefix}${name} where both are untrusted. Other uses of the css helper are not affected.

Workarounds

Do not interpolate untrusted values into css templates, or make sure the text before an interpolated value does not end with <.

Severity

3.4 (Low)


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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 4.13.15"
      },
      "package": {
        "ecosystem": "npm",
        "name": "hono"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.12.0"
            },
            {
              "fixed": "4.13.16"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-126359"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-11-12T23:22:36Z",
    "nvd_published_at": null,
    "severity": "LOW"
  },
  "details": "### Summary\n\nThe `css` helper in `hono/css` escapes a `/` that follows `\u003c` inside an interpolated value so that a value cannot close the `\u003cstyle\u003e` element. The check only looks inside each value. When the text before a value ends with `\u003c`, whether that is the template itself or an earlier interpolated value, and the next value starts with `/`, the `/` is not escaped and the combined output contains an unescaped closing tag.\n\n### Details\n\nInterpolated string values are escaped one at a time before they are joined with the surrounding template text. The rule that neutralizes `\u003c/` therefore cannot see a `\u003c` that belongs to the template. A template such as a `content` declaration that opens with a literal `\u003c` and interpolates a string right after it produces a raw `\u003c/style\u003e` when that string starts with `/style\u003e`. During server-side rendering the `\u003cStyle /\u003e` element is closed early and the rest of the value is interpreted as HTML.\n\nThis issue arises only when `\u003c` is the last character before an interpolation in a `css` template, either written in the template or supplied by a preceding value, and the interpolated value is controlled by a client.\n\n### Impact\n\nA client that controls such a value can inject HTML, including script, into the page rendered on the server.\n\nThis may lead to:\n\n- Execution of attacker-controlled script in the browser of a user who views the page\n- Exposure of information available to that page\n\nThis issue affects applications that interpolate untrusted strings into a `css` template immediately after a `\u003c`, including two adjacent interpolations such as `${prefix}${name}` where both are untrusted. Other uses of the `css` helper are not affected.\n\n### Workarounds\n\nDo not interpolate untrusted values into `css` templates, or make sure the text before an interpolated value does not end with `\u003c`.",
  "id": "GHSA-3gg2-335m-rxc6",
  "modified": "2026-11-12T23:22:37Z",
  "published": "2026-11-12T23:22:36Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/honojs/hono/security/advisories/GHSA-3gg2-335m-rxc6"
    },
    {
      "type": "WEB",
      "url": "https://github.com/honojs/hono/commit/15bbd96ad1b62a0b189db4fd8dc7bf8ef280c513"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/honojs/hono"
    },
    {
      "type": "WEB",
      "url": "https://github.com/honojs/hono/releases/tag/v4.13.16"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Hono: `css` helper does not escape a closing tag split between the template and an interpolated value, allowing HTML injection"
}

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

Order JSON

How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

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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.

Action not permitted

CVE-2026-126359 (GCVE-0-2026-126359)

FKIE_CVE-2026-126359

GHSA-3GG2-335M-RXC6

Summary

Details

Impact

Workarounds

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Sightings

Nomenclature

Vulnerability timeline

Related by attack behaviour